Batteries

11 pages, 786 KiB

Open AccessArticle

The Influence of Micro-Structured Anode Current Collectors in Combination with Highly Concentrated Electrolyte on the Coulombic Efficiency of In-Situ Deposited Li-Metal Electrodes with Different Counter Electrodes

by Fabian Heim, Tina Kreher and Kai Peter Birke

Batteries 2020, 6(1), 20; https://doi.org/10.3390/batteries6010020 - 23 Mar 2020

Cited by 6 | Viewed by 6068

Abstract

This paper compares and combines two common methods to improve the cycle performance of lithium metal (Li) electrodes. One technique is to establish a micro-structured current collector by chemical separation of a copper/zinc alloy. Furthermore, the use of a highly concentrated ether-based electrolyte [...] Read more.

This paper compares and combines two common methods to improve the cycle performance of lithium metal (Li) electrodes. One technique is to establish a micro-structured current collector by chemical separation of a copper/zinc alloy. Furthermore, the use of a highly concentrated ether-based electrolyte is applied as a second approach for improving the cycling behavior. The influence of the two measures compared with a planar current collector and a 1 M concentrated carbonate-based electrolyte, as well as the combination of the methods, are investigated in test cells both with Li and lithium nickel cobalt manganese oxide (NCM) as counter electrodes. In all cases Li is in-situ plated onto the micro-structured current collectors respectively a planar copper foil without presence of any excess Li before first deposition. In experiments with Li counter electrodes, the effect of a structured current collector is not visible whereas the influence of the electrolyte can be observed. With NCM counter electrodes and carbonate-based electrolyte structured current collectors can improve Coulombic efficiency. The confirmation of this outcome in experiments with highly concentrated ether-based electrolyte is challenging due to high deviations. However, these results indicate, that improvements in Coulombic efficiency achieved by structuring the current collector’s surface and using ether-based electrolyte do not necessarily add up, if both methods are combined in one cell. Full article

(This article belongs to the Special Issue Electrochemical, Thermal and Safety Properties of Lithium and Post-Li Materials and Cells)

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12 pages, 3948 KiB

Open AccessArticle

Electrospun Al₂O₃ Film as Inhibiting Corrosion Interlayer of Anode for Solid Aluminum–Air Batteries

by Yuxin Zuo, Ying Yu, Hao Liu, Zhiqing Gu, Qianqian Cao and Chuncheng Zuo

Batteries 2020, 6(1), 19; https://doi.org/10.3390/batteries6010019 - 16 Mar 2020

Cited by 15 | Viewed by 6056

Abstract

Solid Al–air batteries are a promising power source for potable electronics due to their environmentally friendly qualities and high energy density. However, the solid Al–air battery suffers from anodic corrosion and it is difficult to achieve a higher specific capacity. Thus, this work [...] Read more.

Solid Al–air batteries are a promising power source for potable electronics due to their environmentally friendly qualities and high energy density. However, the solid Al–air battery suffers from anodic corrosion and it is difficult to achieve a higher specific capacity. Thus, this work aims at suppressing the corrosion of Al anode by adding an electrospun Al₂O₃ interlayer on to the surface of the anode. The Al₂O₃ interlayer effectively inhibits the self-corrosion of the Al anode. Further, the effects of the thickness of the Al₂O₃ film on corrosion behavior were investigated. The results showed that the Al–air battery with a 4 μm Al₂O₃ interlayer is more suitable for a low current density discharge, which could be applied for mini-watt devices. With a proper thickness of the Al₂O₃ interlayer, corrosion of the anode was considerably suppressed without sacrificing the discharge voltage at a low current density. The Al–air battery with a 4 μm Al₂O₃ interlayer provided a significantly high capacity (1255 mAh/g at 5 mA/cm²) and an excellent stability. This wo presents a promising approach for fabricating an inhibiting corrosion interlayer for solid Al–air battery designed for mini-watt devices. Full article

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2 pages, 175 KiB

Open AccessEditorial

Batteries and Supercapacitors Aging

by Pascal Venet and Eduardo Redondo-Iglesias

Batteries 2020, 6(1), 18; https://doi.org/10.3390/batteries6010018 - 12 Mar 2020

Cited by 4 | Viewed by 4488

Abstract

Electrochemical energy storage is a key element of systems in a wide range of sectors, such as electro-mobility, portable devices, or renewable energy [...] Full article

(This article belongs to the Special Issue Batteries and Supercapacitors Aging)

11 pages, 2615 KiB

Open AccessArticle

Thermal Analysis of Cold Plate with Different Configurations for Thermal Management of a Lithium-Ion Battery

by Seyed Saeed Madani, Erik Schaltz and Søren Knudsen Kær

Batteries 2020, 6(1), 17; https://doi.org/10.3390/batteries6010017 - 9 Mar 2020

Cited by 18 | Viewed by 6518

Abstract

Thermal analysis and thermal management of lithium-ion batteries for utilization in electric vehicles is vital. In order to investigate the thermal behavior of a lithium-ion battery, a liquid cooling design is demonstrated in this research. The influence of cooling direction and conduit distribution [...] Read more.

Thermal analysis and thermal management of lithium-ion batteries for utilization in electric vehicles is vital. In order to investigate the thermal behavior of a lithium-ion battery, a liquid cooling design is demonstrated in this research. The influence of cooling direction and conduit distribution on the thermal performance of the lithium-ion battery is analyzed. The outcomes exhibit that the appropriate flow rate for heat dissipation is dependent on different configurations for cold plate. The acceptable heat dissipation condition could be acquired by adding more cooling conduits. Moreover, it was distinguished that satisfactory cooling direction could efficiently enhance the homogeneity of temperature distribution of the lithium-ion battery. Full article

(This article belongs to the Special Issue Thermal and Safety Properties of Materials, Cells and Batteries 2019)

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17 pages, 2497 KiB

Open AccessArticle

Behavior of Battery Metals Lithium, Cobalt, Manganese and Lanthanum in Black Copper Smelting

by Anna Dańczak, Lassi Klemettinen, Matti Kurhila, Pekka Taskinen, Daniel Lindberg and Ari Jokilaakso

Batteries 2020, 6(1), 16; https://doi.org/10.3390/batteries6010016 - 2 Mar 2020

Cited by 15 | Viewed by 7796

Abstract

Recycling of metals from different waste streams must be increased in the near future for securing the availability of metals that are critical for high-tech applications, such as batteries for e-mobility. Black copper smelting is a flexible recycling route for many different types [...] Read more.

Recycling of metals from different waste streams must be increased in the near future for securing the availability of metals that are critical for high-tech applications, such as batteries for e-mobility. Black copper smelting is a flexible recycling route for many different types of scrap, including Waste Electrical and Electronic Equipment (WEEE) and some end-of-life energy storage materials. Fundamental thermodynamic data about the behavior of battery metals and the effect of slag additives is required for providing data necessary for process development, control, and optimization. The goal of our study is to investigate the suitability of black copper smelting process for recycling of battery metals lithium, cobalt, manganese, and lanthanum. The experiments were performed alumina crucibles at 1300 °C, in oxygen partial pressure range of 10⁻¹¹–10⁻⁸ atm. The slags studied contained 0 to 6 wt% of MgO. Electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) techniques were utilized for phase composition quantifications. The results reveal that most cobalt can be recovered into the copper alloy in extremely reducing process conditions, whereas lithium, manganese, and lanthanum deport predominantly in the slag at all investigated oxygen partial pressures. Full article

(This article belongs to the Special Issue Circular Battery Technologies)

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10 pages, 1947 KiB

Open AccessArticle

Development of Flow Fields for Zinc Slurry Air Flow Batteries

by Nak Heon Choi, Diego del Olmo, Peter Fischer, Karsten Pinkwart and Jens Tübke

Batteries 2020, 6(1), 15; https://doi.org/10.3390/batteries6010015 - 1 Mar 2020

Cited by 10 | Viewed by 7248

Abstract

The flow field design and material composition of the electrode plays an important role in the performance of redox flow batteries, especially when using highly viscous liquids. To enhance the discharge power density of zinc slurry air flow batteries, an optimum slurry distribution [...] Read more.

The flow field design and material composition of the electrode plays an important role in the performance of redox flow batteries, especially when using highly viscous liquids. To enhance the discharge power density of zinc slurry air flow batteries, an optimum slurry distribution in the cell is key. Hence, several types of flow fields (serpentine, parallel, plastic flow frames) were tested in this study to improve the discharge power density of the battery. The serpentine flow field delivered a power density of 55 mW∙cm⁻², while parallel and flow frame resulted in 30 mW∙cm⁻² and 10 mW∙cm⁻², respectively. Moreover, when the anode bipolar plate material was changed from graphite to copper, the power density of the flow frame increased to 65 mW∙cm⁻², and further improvement was attained when the bipolar plate material was further changed to copper–nickel. These results show the potential to increase the power density of slurry-based flow batteries by flow field optimization and design of bipolar plate materials. Full article

(This article belongs to the Special Issue Batteries: Feature Papers 2020)

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18 pages, 1543 KiB

Open AccessArticle

Modelling Lithium-Ion Battery Ageing in Electric Vehicle Applications—Calendar and Cycling Ageing Combination Effects

by Eduardo Redondo-Iglesias, Pascal Venet and Serge Pelissier

Batteries 2020, 6(1), 14; https://doi.org/10.3390/batteries6010014 - 19 Feb 2020

Cited by 53 | Viewed by 15732

Abstract

Battery ageing is an important issue in e-mobility applications. The performance degradation of lithium-ion batteries has a strong influence on electric vehicles’ range and cost. Modelling capacity fade of lithium-ion batteries is not simple: many ageing mechanisms can exist and interact. Because calendar [...] Read more.

Battery ageing is an important issue in e-mobility applications. The performance degradation of lithium-ion batteries has a strong influence on electric vehicles’ range and cost. Modelling capacity fade of lithium-ion batteries is not simple: many ageing mechanisms can exist and interact. Because calendar and cycling ageings are not additive, a major challenge is to model battery ageing in applications where the combination of cycling and rest periods are variable as, for example, in the electric vehicle application. In this work, an original approach to capacity fade modelling based on the formulation of reaction rate of a two-step reaction is proposed. A simple but effective model is obtained: based on only two differential equations and seven parameters, it can reproduce the capacity evolution of lithium-ion cells subjected to cycling profiles similar to those found in electric vehicle applications. Full article

(This article belongs to the Special Issue Batteries and Supercapacitors Aging Ⅱ)

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17 pages, 4630 KiB

Open AccessArticle

Inhomogeneous Temperature Distribution Affecting the Cyclic Aging of Li-Ion Cells. Part I: Experimental Investigation

by Daniel Werner, Sabine Paarmann, Achim Wiebelt and Thomas Wetzel

Batteries 2020, 6(1), 13; https://doi.org/10.3390/batteries6010013 - 14 Feb 2020

Cited by 27 | Viewed by 7531

Abstract

Alongside electrical loads, it is known that temperature has a strong influence on battery behavior and lifetime. Investigations have mainly been performed at homogeneous temperatures and non-homogeneous conditions in single cells have at best been simulated. This publication presents the development of a [...] Read more.

Alongside electrical loads, it is known that temperature has a strong influence on battery behavior and lifetime. Investigations have mainly been performed at homogeneous temperatures and non-homogeneous conditions in single cells have at best been simulated. This publication presents the development of a methodology and experimental setup to investigate the influence of thermal boundary conditions during the operation of lithium-ion cells. In particular, spatially inhomogeneous and transient thermal boundary conditions and periodical electrical cycles were superimposed in different combinations. This required a thorough design of the thermal boundary conditions applied to the cells. Unlike in other contributions that rely on placing cells in a climatic chamber to control ambient air temperature, here the cell surfaces and tabs were directly connected to individual cooling and heating plates. This improves the control of the cells’ internal temperature, even with high currents accompanied by strong internal heat dissipation. The aging process over a large number of electrical cycles is presented by means of discharge capacity and impedance spectra determined in repeated intermediate characterizations. The influence of spatial temperature gradients and temporal temperature changes on the cyclic degradation is revealed. It appears that the overall temperature level is indeed a decisive parameter for capacity fade during cyclic aging, while the intensity of a temperature gradient is not as essential. Furthermore, temperature changes can have a substantial impact and potentially lead to stronger degradation than spatial inhomogeneities. Full article

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16 pages, 3094 KiB

Open AccessEditor’s ChoiceArticle

Inhomogeneous Temperature Distribution Affecting the Cyclic Aging of Li-Ion Cells. Part II: Analysis and Correlation

by Daniel Werner, Sabine Paarmann, Achim Wiebelt and Thomas Wetzel

Batteries 2020, 6(1), 12; https://doi.org/10.3390/batteries6010012 - 14 Feb 2020

Cited by 32 | Viewed by 6668

Abstract

Temperature has a significant influence on the behavior of batteries and their lifetime. There are several studies in literature that investigate the aging behavior under electrical load, but are limited to homogeneous, constant temperatures. This article presents an approach to quantifying cyclic aging [...] Read more.

Temperature has a significant influence on the behavior of batteries and their lifetime. There are several studies in literature that investigate the aging behavior under electrical load, but are limited to homogeneous, constant temperatures. This article presents an approach to quantifying cyclic aging of lithium-ion cells that takes into account complex thermal boundary conditions. It not only considers different temperature levels but also spatial and transient temperature gradients that can occur despite-or even due to-the use of thermal management systems. Capacity fade and impedance rise are used as measured quantities for degradation and correlated with the temperature boundary conditions during the aging process. The concept and definition of an equivalent aging temperature (EAT) is introduced to relate the degradation caused by spatial and temporal temperature inhomogeneities to similar degradation caused by a homogeneous steady temperature during electrical cycling. The results show an increased degradation at both lower and higher temperatures, which can be very well described by two superimposed exponential functions. These correlations also apply to cells that are cycled under the influence of spatial temperature gradients, both steady and transient. Only cells that are exposed to transient, but spatially homogeneous temperature conditions show a significantly different aging behavior. The concluding result is a correlation between temperature and aging rate, which is expressed as degradation per equivalent full cycle (EFC). This enables both temperature-dependent modeling of the aging behavior and its prediction. Full article

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41 pages, 6949 KiB

Open AccessArticle

Comparison of Single-Ion Conducting Polymer Gel Electrolytes for Sodium, Potassium, and Calcium Batteries: Influence of Polymer Chemistry, Cation Identity, Charge Density, and Solvent on Conductivity

by Hunter O. Ford, Chuanchuan Cui and Jennifer L. Schaefer

Batteries 2020, 6(1), 11; https://doi.org/10.3390/batteries6010011 - 13 Feb 2020

Cited by 23 | Viewed by 8527

Abstract

From the standpoint of material diversification and sustainability, the development of so-called “beyond lithium-ion” battery chemistries is important for the future of energy storage. Na, K, and Ca are promising as the basis for battery chemistries in that these elements are highly abundant. [...] Read more.

From the standpoint of material diversification and sustainability, the development of so-called “beyond lithium-ion” battery chemistries is important for the future of energy storage. Na, K, and Ca are promising as the basis for battery chemistries in that these elements are highly abundant. Here, a series of single-ion conducting polymer electrolytes (SIPEs) for Na, K, and Ca batteries are synthesized and investigated. The two classes of metal cation neutralized SIPEs compared are crosslinked poly(ethylene glycol) dimethacrylate-x-styrene sulfonate (PEGDMA-SS) and poly(tetrahydrofuran) diacrylate-x-4-styrenesulfonyl (trifluoromethylsulfonyl)imide (PTHFDA-STFSI); three cation types, three charge densities, and four swelling states are examined. The impact on conductivity of all of these parameters is studied, and in conjunction with small angle X-ray scattering (SAXS), it is found that promoting ion dissociation and preventing the formation of dense ionic aggregates facilitates ion transport. These results indicate many of the lessons learned from the Li SIPE literature can be translated to beyond Li chemistries. At 25 °C, the best performing Na/K and Ca exchanged polymers yield active cation conductivity on the order of 10⁻⁴ S/cm and 10⁻⁶ S/cm, respectively, for ethylene carbonate:propylene carbonate gelled SIPEs, and 10⁻⁵ S/cm and 10⁻⁷ S/cm, respectively, for glyme gelled SIPEs. Full article

(This article belongs to the Special Issue Batteries: Feature Papers 2020)

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17 pages, 5066 KiB

Open AccessArticle

In Situ Measurement of Orthotropic Thermal Conductivity on Commercial Pouch Lithium-Ion Batteries with Thermoelectric Device

by Luigi Aiello, Georgi Kovachev, Bernhard Brunnsteiner, Martin Schwab, Gregor Gstrein, Wolfgang Sinz and Christian Ellersdorfer

Batteries 2020, 6(1), 10; https://doi.org/10.3390/batteries6010010 - 10 Feb 2020

Cited by 12 | Viewed by 7440

Abstract

In this paper, the direct measurement of the orthotropic thermal conductivity on a commercial Li-ion pouch battery is presented. The samples under analysis are state-of-the art batteries obtained from a fully electric vehicle commercialized in 2016. The proposed methodology does not require a [...] Read more.

In this paper, the direct measurement of the orthotropic thermal conductivity on a commercial Li-ion pouch battery is presented. The samples under analysis are state-of-the art batteries obtained from a fully electric vehicle commercialized in 2016. The proposed methodology does not require a laboratory equipped to manage hazardous chemical substances as the battery does not need to be disassembled. The principle of the measurement methodology consists of forcing a thermal gradient on the battery along the desired direction and measuring the heat flux and temperature after the steady state condition has been reached. A thermoelectric device has been built in order to force the thermal gradient and keep it stable over a long period of time in order to be able to observe the temperatures in steady state condition. Aligned with other measurement methodologies, the results revealed that the thermal conductivity in the thickness direction (0.77 Wm⁻¹K⁻¹) is lower with respect to the other two directions (25.55 Wm⁻¹K⁻¹ and 25.74 Wm⁻¹K⁻¹) to about a factor ×35. Full article

(This article belongs to the Special Issue Thermal and Safety Properties of Materials, Cells and Batteries 2019)

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8 pages, 923 KiB

Open AccessViewpoint

Corrections of Voltage Loss in Hydrogen-Oxygen Fuel Cells

by Jinzhe Lyu, Viktor Kudiiarov and Andrey Lider

Batteries 2020, 6(1), 9; https://doi.org/10.3390/batteries6010009 - 6 Feb 2020

Cited by 3 | Viewed by 6121

Abstract

Normally, the Nernst voltage calculated from the concentration of the reaction gas in the flow channel is considered to be the ideal voltage (reversible voltage) of the hydrogen-oxygen fuel cell. The Nernst voltage loss in fuel cells in most of the current literature [...] Read more.

Normally, the Nernst voltage calculated from the concentration of the reaction gas in the flow channel is considered to be the ideal voltage (reversible voltage) of the hydrogen-oxygen fuel cell. The Nernst voltage loss in fuel cells in most of the current literature is thought to be due to the difference in concentration of reaction gas in the flow channel and concentration of reaction gas on the catalyst layer at the time as when the high net current density is generated. Based on the Butler–Volmer equation in the hydrogen-oxygen fuel cell, this paper demonstrates that Nernst voltage loss caused by concentration difference of reaction gas in the flow channel and reaction gas on the catalyst layer at equilibrium potential. According to the relationship between the current density and the concentration difference it can be proven that Nernst voltage loss does not exist in hydrogen-oxygen fuel cells because there is no concentration difference of reaction gas in the flow channel and on the catalytic layer at equilibrium potential when the net current density is zero. Full article

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Graphical abstract

26 pages, 5912 KiB

Open AccessEditor’s ChoiceReview

Degradation and Aging Routes of Ni-Rich Cathode Based Li-Ion Batteries

by Philipp Teichert, Gebrekidan Gebresilassie Eshetu, Hannes Jahnke and Egbert Figgemeier

Batteries 2020, 6(1), 8; https://doi.org/10.3390/batteries6010008 - 22 Jan 2020

Cited by 81 | Viewed by 23890

Abstract

Driven by the increasing plea for greener transportation and efficient integration of renewable energy sources, Ni-rich metal layered oxides, namely NMC, Li [Ni_1−x−yCo_yMn_z] O₂ (x + y ≤ 0.4), and NCA, Li [...] Read more.

Driven by the increasing plea for greener transportation and efficient integration of renewable energy sources, Ni-rich metal layered oxides, namely NMC, Li [Ni_1−x−yCo_yMn_z] O₂ (x + y ≤ 0.4), and NCA, Li [Ni_1−x−yCo_xAl_y] O₂, cathode materials have garnered huge attention for the development of Next-Generation lithium-ion batteries (LIBs). The impetus behind such huge celebrity includes their higher capacity and cost effectiveness when compared to the-state-of-the-art LiCoO₂ (LCO) and other low Ni content NMC versions. However, despite all the beneficial attributes, the large-scale deployment of Ni-rich NMC based LIBs poses a technical challenge due to less stability of the cathode/electrolyte interphase (CEI) and diverse degradation processes that are associated with electrolyte decomposition, transition metal cation dissolution, cation–mixing, oxygen release reaction etc. Here, the potential degradation routes, recent efforts and enabling strategies for mitigating the core challenges of Ni-rich NMC cathode materials are presented and assessed. In the end, the review shed light on the perspectives for the future research directions of Ni-rich cathode materials. Full article

(This article belongs to the Special Issue Batteries and Supercapacitors Aging)

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3 pages, 209 KiB

Open AccessEditorial

Acknowledgement to Reviewers of Batteries in 2019

by Batteries Editorial Office

Batteries 2020, 6(1), 7; https://doi.org/10.3390/batteries6010007 - 21 Jan 2020

Viewed by 3487

Abstract

The editorial team greatly appreciates the reviewers who have dedicated their considerable time and expertise to the journal’s rigorous editorial process over the past 12 months, regardless of whether the papers are finally published or not [...] Full article

18 pages, 5454 KiB

Open AccessEditor’s ChoiceArticle

Accelerated Aging Characterization of Lithium-ion Cells: Using Sensitivity Analysis to Identify the Stress Factors Relevant to Cyclic Aging

by Tanja Gewald, Adrian Candussio, Leo Wildfeuer, Dirk Lehmkuhl, Alexander Hahn and Markus Lienkamp

Batteries 2020, 6(1), 6; https://doi.org/10.3390/batteries6010006 - 20 Jan 2020

Cited by 22 | Viewed by 12459

Abstract

As storage technology in electric vehicles, lithium-ion cells are subject to a continuous aging process during their service life that, in the worst case, can lead to a premature system failure. Battery manufacturers thus have an interest in the aging prediction during the [...] Read more.

As storage technology in electric vehicles, lithium-ion cells are subject to a continuous aging process during their service life that, in the worst case, can lead to a premature system failure. Battery manufacturers thus have an interest in the aging prediction during the early design phase, for which semi-empirical aging models are often used. The progress of aging is dependent on the application-specific load profile, more precisely on the aging-relevant stress factors. Still, a literature review reveals a controversy on the aging-relevant stress factors to use as input parameters for the simulation models. It shows that, at present, a systematic and efficient procedure for stress factor selection is missing, as the aging characteristic is cell-specific. In this study, an accelerated sensitivity analysis as a prior step to aging modeling is proposed, which is transferable and allows to determine the actual aging-relevant stress factors for a specific lithium-ion cell. For the assessment of this accelerated approach, two test series with different acceleration levels and cell types are performed and evaluated. The results show that a certain amount of charge throughput, 100 equivalent full cycles in this case, is necessary to conduct a statistically significant sensitivity analysis. Full article

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12 pages, 3577 KiB

Open AccessArticle

Synthesis of a NiMoO₄/3D-rGO Nanocomposite via Starch Medium Precipitation Method for Supercapacitor Performance

by Shahrzad Arshadi Rastabi, Rasoul Sarraf Mamoory, Nicklas Blomquist, Manisha Phadatare and Håkan Olin

Batteries 2020, 6(1), 5; https://doi.org/10.3390/batteries6010005 - 15 Jan 2020

Cited by 16 | Viewed by 5860

Abstract

This paper presents research on the synergistic effects of nickel molybdate and reduced graphene oxide as a nanocomposite for further development of energy storage systems. An enhancement in the electrochemical performance of supercapacitor electrodes occurs by synthesizing highly porous structures and achieving more [...] Read more.

This paper presents research on the synergistic effects of nickel molybdate and reduced graphene oxide as a nanocomposite for further development of energy storage systems. An enhancement in the electrochemical performance of supercapacitor electrodes occurs by synthesizing highly porous structures and achieving more surface area. In this work, a chemical precipitation technique was used to synthesize the NiMoO₄/3D-rGO nanocomposite in a starch media. Starch was used to develop the porosities of the nanostructure. A temperature of 350 °C was applied to transform graphene oxide sheets to reduced graphene oxide and remove the starch to obtain the NiMoO₄/3D-rGO nanocomposite with porous structure. The X-ray diffraction pattern of the NiMoO₄ nano particles indicated a monoclinic structure. Also, the scanning electron microscope observation showed that the NiMoO₄ NPs were dispersed across the rGO sheets. The electrochemical results of the NiMoO₄/3D-rGO electrode revealed that the incorporation of rGO sheets with NiMoO₄ NPs increased the capacity of the nanocomposite. Therefore, a significant increase in the specific capacity of the electrode was observed with the NiMoO₄/3D-rGO nanocomposite (450 Cg⁻¹ or 900 Fg⁻¹) when compared with bare NiMoO₄ nanoparticles (350 Cg⁻¹ or 700 Fg⁻¹) at the current density of 1 A g⁻¹. Our findings show that the incorporation of rGO and NiMoO₄ NP redox reactions with a porous structure can benefit the future development of supercapacitors. Full article

(This article belongs to the Special Issue Electrochemical Capacitors)

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13 pages, 4589 KiB

Open AccessArticle

State-of-Charge Monitoring and Battery Diagnosis of NiCd Cells Using Impedance Spectroscopy

by Peter Kurzweil and Wolfgang Scheuerpflug

Batteries 2020, 6(1), 4; https://doi.org/10.3390/batteries6010004 - 9 Jan 2020

Cited by 11 | Viewed by 11316

Abstract

With respect to aeronautical applications, the state-of-charge (SOC) and state-of-health (SOH) of rechargeable nickel–cadmium batteries was investigated with the help of the frequency-dependent reactance Im Z(ω) and the pseudo-capacitance C(ω) in the frequency range between 1 kHz [...] Read more.

With respect to aeronautical applications, the state-of-charge (SOC) and state-of-health (SOH) of rechargeable nickel–cadmium batteries was investigated with the help of the frequency-dependent reactance Im Z(ω) and the pseudo-capacitance C(ω) in the frequency range between 1 kHz and 0.1 Hz. The method of SOC monitoring using impedance spectroscopy is evaluated with the example of 1.5-year long-term measurements of commercial devices. A linear correlation between voltage and capacitance is observed as long as overcharge and deep discharge are avoided. Pseudo-charge Q(ω) = C(ω)⋅U at 1 Hz with respect to the rated capacity is proposed as a reliable SOH indicator for rapid measurements. The benefit of different evaluation methods and diagram types for impedance data is outlined. Full article

(This article belongs to the Special Issue Batteries and Supercapacitors Aging)

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26 pages, 6857 KiB

Open AccessEditor’s ChoiceArticle

The Impact of Environmental Factors on the Thermal Characteristic of a Lithium–ion Battery

by Gerd Liebig, Ulf Kirstein, Stefan Geißendörfer, Omio Zahid, Frank Schuldt and Carsten Agert

Batteries 2020, 6(1), 3; https://doi.org/10.3390/batteries6010003 - 2 Jan 2020

Cited by 23 | Viewed by 9982 | Correction

Abstract

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 [...] Read more.

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40

Ah

prismatic lithium–ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries’ interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations; (2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell; (3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries’ lifespan. Full article

(This article belongs to the Special Issue Thermal Characteristics of Batteries 2019)

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16 pages, 7920 KiB

Open AccessArticle

Measuring Test Bench with Adjustable Thermal Connection of Cells to Their Neighbors and a New Model Approach for Parallel-Connected Cells

by Alexander Fill, Tobias Mader, Tobias Schmidt, Raphael Llorente and Kai Peter Birke

Batteries 2020, 6(1), 2; https://doi.org/10.3390/batteries6010002 - 26 Dec 2019

Cited by 15 | Viewed by 6116

Abstract

This article presents a test bench with variable temperature control of the individual cells connected in parallel. This allows to reconstruct arising temperature gradients in a battery module and to investigate their effects on the current distribution. The influence of additional contact resistances [...] Read more.

This article presents a test bench with variable temperature control of the individual cells connected in parallel. This allows to reconstruct arising temperature gradients in a battery module and to investigate their effects on the current distribution. The influence of additional contact resistances induced by the test bench is determined and minimized. The contact resistances are reduced from

R_{Tab +} = 81.18

μ Ω

to

R_{Tab +} = 55.15

μ Ω

at the positive respectively from

R_{Tab -} = 35.59

μ Ω

to

R_{Tab -} = 28.2

μ Ω

at the negative tab by mechanical and chemical treating. An increase of the contact resistance at the positive tab is prevented by air seal of the contact. The resistance of the load cable must not be arbitrarily small, as the cable is used as a shunt for current measurement. In order to investigate their impacts, measurements with two parallel-connected cells and different load cables with a resistance of

R_{Cab +} = 0.3

m

Ω

,

R_{Cab +} = 1.6

m

Ω

and

R_{Cab +} = 4.35

m

Ω

are conducted. A shift to lower current differences with decreasing cable resistance but qualitatively the same dynamic of the current distribution is found. An extended dual polarization model is introduced, considering the current distribution within the cells as well as the additional resistances induced by the test bench. The model shows a high correspondence to measurements with two parallel-connected cells, with a Root Mean Square Deviation (RMSD) of

ξ_{RMSD} = 0.083

A. Full article

(This article belongs to the Special Issue Battery Management Systems of Electric and Hybrid Electric Vehicles)

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16 pages, 2760 KiB

Open AccessArticle

Sensor Fault Detection and Isolation for Degrading Lithium-Ion Batteries in Electric Vehicles Using Parameter Estimation with Recursive Least Squares

by Manh-Kien Tran and Michael Fowler

Batteries 2020, 6(1), 1; https://doi.org/10.3390/batteries6010001 - 20 Dec 2019

Cited by 59 | Viewed by 9513

Abstract

With the increase in usage of electric vehicles (EVs), the demand for Lithium-ion (Li-ion) batteries is also on the rise. The battery management system (BMS) plays an important role in ensuring the safe and reliable operation of the battery in EVs. Sensor faults [...] Read more.

With the increase in usage of electric vehicles (EVs), the demand for Lithium-ion (Li-ion) batteries is also on the rise. The battery management system (BMS) plays an important role in ensuring the safe and reliable operation of the battery in EVs. Sensor faults in the BMS can have significant negative effects on the system, hence it is important to diagnose these faults in real-time. Existing sensor fault detection and isolation (FDI) methods have not considered battery degradation. Degradation can affect the long-term performance of the battery and cause false fault detection. This paper presents a model-based sensor FDI scheme for a Li-ion cell undergoing degradation. The proposed scheme uses the recursive least squares (RLS) method to estimate the equivalent circuit model (ECM) parameters in real time. The estimated ECM parameters are put through weighted moving average (WMA) filters, and then cumulative sum control charts (CUSUM) are implemented to detect any significant deviation between unfiltered and filtered data, which would indicate a fault. The current and voltage faults are isolated based on the responsiveness of the parameters when each fault occurs. The proposed FDI scheme is then validated through conducting a series of experiments and simulations. Full article

(This article belongs to the Special Issue Battery Management Systems of Electric and Hybrid Electric Vehicles)

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Batteries, Volume 6, Issue 1 (March 2020) – 20 articles

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