Search Results (34)

Lithium-ion batteries (LIBs) have attracted extensive attention as a distinguished electrochemical energy storage system due to their high energy density and long cycle life. However, the initial irreversible lithium loss during the first cycle caused by the formation of the solid electrolyte interphase (SEI) leads to the prominent reduction in the energy density of LIBs. Notably, lithium formate (HCOOLi, LFM) is regarded as a promising cathode prelithiation reagent for effective lithium supplementation due to its high theoretical capacity of 515 mAh·g⁻¹. Nevertheless, the stable Li-O bond of LFM brings out the high reaction barrier accompanied by the high decomposition potential, which impedes its practical applications. To address this issue, a feasible strategy for reducing the reaction barrier has been proposed, in which the decomposition potential of LFM from 4.84 V to 4.23 V resulted from the synergetic effects of improving the electron/ion transport kinetics and catalysis of transition metal oxides. The addition of LFM to full cells consisting of graphite anodes and LiNi_0.834Co_0.11Mn_0.056O₂ cathodes significantly enhanced the electrochemical performance, increasing the reversible discharge capacity from 156 to 169 mAh·g⁻¹ at 0.1 C (2.65–4.25 V). Remarkably, the capacity retention after 100 cycles improved from 72.8% to 94.7%. Our strategy effectively enables LFM to serve as an efficient prelithiation additive for commercial cathode materials. Full article

Prelithiation has been widely accepted as one of the most promising strategies to compensate for the loss of active substance and to improve the initial Coulombic efficiency in silicon-based anodes for advanced high-energy-density batteries. But because of their unstable solid electrolyte interface (SEI) layer and low initial Coulombic efficiency, they expand in volume during prelithiation and react with moisture, which makes commercialization a difficult process. Herein, we have developed a strategy using lithium bis(fluorosulfonyl)imide (LiFSI) treatment to eliminate redundant lithium and generate LiF-based inorganic compounds on the surface of the prelithiated electrode. Such method not only reduces the reactiveness of the prelithiated anode but also enhances the ionic conductivity of the SEI. The rich LiF surface works as an artificial SEI, and according to electrochemical evaluation, the initial Coulombic efficiency of the prelithiated silicon anode treated with LiFSI can reach 92.9%. This technique not only increases the battery’s energy density but also its cycle stability, resulting in superior capacity retention and a longer cycling life. Full article

As the global energy demand continues to rise, the utilization of lithium-ion capacitors (LICs), which combine the advantages of lithium-ion batteries (LIBs) and electrochemical capacitors (ECs), is also increasing. LICs offer high energy density, high power density, and a long life cycle. However, a prelithiation process is required for graphite-based anode materials. In LICs, the formation of the solid electrolyte interphase (SEI) layer inevitably causes an initial irreversible capacity loss, often resulting in the excessive consumption of lithium ions. Considering the limited lithium resources, prelithiation is essential to achieve a satisfactory electrochemical performance in LICs. Various anode prelithiation techniques have been reported to enhance the capacity of LIBs and LICs. Among these, the direct-contact prelithiation method involves physically contacting lithium metal with the electrode or active material. In this study, direct-contact prelithiation was performed on soft carbon-based anode materials, and LICs were fabricated using activated carbon-based cathode materials. The electrochemical properties of the fabricated LICs were evaluated to demonstrate the feasibility of applying the direct-contact prelithiation technique. Full article

Pre-lithiation using Li–Si alloy-type additives is a promising technical approach to address the drawbacks of Si-based anodes, such as a low initial Coulombic efficiency (ICE) and inevitable capacity decay during cycling. However, its commercial application is limited by the air sensitivity of the highly reactive Li–Si alloys, which demands improved environmental stability. In this work, a protective membrane is constructed on Li₁₃Si₄ alloys using low-surface-energy paraffin and highly conductive carbon nanotubes through liquid-phase deposition, exhibiting enhanced hydrophobicity and improved Li⁺/e⁻ conductivity. The Li₁₃Si₄@Paraffin/carbon nanotubes (Li₁₃Si₄@P-CNTs) composite achieves a high pre-lithiation capacity of 970 mAh g⁻¹ and superb environmental stability, retaining 92.2% capacity after exposure to ambient air with 45% relative humidity. DFT calculations and in situ XRD measurements reveal that the paraffin-dominated coating membrane, featuring weak dipole–dipole interactions with water molecules, effectively reduces the moisture-induced oxidation kinetics of Li₁₃Si₄@P-CNTs in air. Electrochemical kinetic analysis and XPS depth profiling reveal the enhancement in charge transfer dynamics and surface Li⁺ transport kinetics (SEI rich in inorganic lithium salts) in P-SiO@C pre-lithiated by Li₁₃Si₄@P-CNTs pre-lithiation additives. Benefitting from pre-lithiation via Li₁₃Si₄@P-CNTs, the pre-lithiated SiO@C(P-SiO@C) delivers high ICE (103.7%), stable cycling performance (981 mAh g⁻¹ at 200 cycles) and superior rate performance (474.5 mAh g⁻¹ at 3C) in a half-cell system. The LFP||P-Gr pouch-type full cell exhibits a capacity retention of 83.2% (2500 cycles) and an energy density of 381 Wh kg⁻¹ after 2500 cycles. The Li₁₃Si₄@P-CNTs additives provide valuable design concepts for the development of pre-lithiation materials. Full article

Although silicon-based anodes have been identified as a potential alternative to conventional graphite anodes, the huge volume change (approximately 300%) that occurs in silicon while cycling still impedes this system from practical applications. In the case of silicon-suboxide (SiO_x)-based anode materials, both Li₂O and LiSiO₄ are formed during the initial lithiation processes and act as a natural volume buffer matrix to accommodate volume changes and the formation of a stable SEI layer, which improves the cyclability and capacity retention. In this study, a series of SiO_x/Si/C-based electrodes composed of different amorphous SiO_x, Si, and graphitic carbon contents were prepared. Among the various investigated compositions, the electrode with a ratio of SiO_x-Si-C equal to 70:12.5:12.5 was found to be optimal in terms of discharge capacity. This promising electrode was pre-lithiated prior to cycling. Finally, 2032-type lithium–sulfur (Li-S) coin cells composed of a S-C/SiO_x-Si-C (pre-lithiated) configuration were assembled and their cycling performances are reported. Full article

Cathodes undergo unavoidable lithium loss due to the formation of a solid electrolyte interface (SEI), which seriously affects the energy density of lithium iron phosphate (LFP) batteries. To compensate for the initial capacity loss, we introduced an NiCo-Li₂Se nanocomposite to an LFP battery system to act as a competitive cathode prelithiation additive. Benefiting from its zero gas-emissions, ambient stability, high irreversible capacity, low delithiation potential, and good compatibility with carbonate-based electrolytes, the NiCo-Li₂Se additive based on the chemical conversion reaction effectively offset the initial lithium loss. As a result, with 10 wt% addition, the initial charge capacity of the Li||LFP half-cell was improved by 34 mA h g⁻¹. The Gra||LFP-Li₂Se full-cell released an initial discharge specific capacity of 159.7 mA h g⁻¹, which increased by 18% compared with the Gra||LFP full-cell, resulting in improved cycling stability. In addition, COMSOL Multiphysics simulation was applied to verify the function of the NiCo-Li₂Se additive, and pouch cells were assembled to explore its potential in large-scale industrial application. This work provides a meaningful research direction for the design of a prelithiation additive for LFP cells. Full article

In conventional lithium-ion batteries (LIBs), the active lithium from the lithium-containing cathode is consumed by the formation of a solid electrolyte interface (SEI) at the anode during the first charge, resulting in irreversible capacity loss. Prelithiation additives can provide additional active lithium to effectively compensate for lithium loss. Lithium oxalate is regarded as a promising ideal cathode prelithiation agent; however, the electrochemical decomposition of lithium oxalate is challenging. In this work, a hollow and porous composite microsphere was prepared using a mixture of lithium oxalate, Ketjen Black and transition metal oxide catalyst, and the formulation was optimized. Owing to the compositional and structural merits, the decomposition voltage of lithium oxalate in the microsphere was reduced to 3.93 V; when being used as an additive, there is no noticeable side effect on the performance of the cathode material. With 4.2% of such an additive, the first discharge capacity of the LiFePO4‖graphite full cell increases from 139.1 to 151.9 mAh g⁻¹, and the coulombic efficiency increases from 88.1% to 96.3%; it also facilitates the formation of a superior SEI, leading to enhanced cycling stability. This work provides an optimized formula for developing an efficient prelithiation agent for LIBs. Full article

Developing electrode materials with high voltage and high specific capacity has always been an important strategy for increasing the energy density of lithium-ion capacitors (LICs). However, organic-based electrolytes with lithium salts limit their potential for application in LICs to voltages below 3.8 V in terms of polarization reactions. In this work, we introduce Li[N(C₂F₅SO₂)₂] (lithium Bis (pentafluoroethanesulfonyl)imide or LiBETI), an electrolyte with high conductivity and superior electrochemical and mechanical stability, to construct a three-electrode LIC system. After graphite anode pre-lithiation, the anode potential was stabilized in the three-electrode LIC system, and a stable solid electrolyte interface (SEI) film formed on the anode surface as expected. Meanwhile, the LIC device using LiBETI as the electrolyte, and a self-synthesized graphene/single-walled carbon nanotube (SWCNT) composite as the cathode, showed a high voltage window, allowing the LIC to achieve an operating voltage of 4.5 V. As a result, the LIC device has a high energy density of up to 182 Wh kg⁻¹ and a 2678 W kg⁻¹ power density at 4.5 V. At a current density of 2 A g⁻¹, the capacity retention rate is 72.7% after 10,000 cycles. Full article

Developments in different battery chemistries and cell formats play a vital role in the final performance of the batteries found in the market. However, battery manufacturing process steps and their product quality are also important parameters affecting the final products’ operational lifetime and durability. In this review paper, we have provided an in-depth understanding of lithium-ion battery manufacturing in a chemistry-neutral approach starting with a brief overview of existing Li-ion battery manufacturing processes and developing a critical opinion of future prospectives, including key aspects such as digitalization, upcoming manufacturing technologies and their scale-up potential. In this sense, the review paper will promote an understanding of the process parameters and product quality. Full article

Silicon (Si) has been considered to be one of the most promising anode materials for high energy density lithium−ion batteries (LIBs) due to its high theoretical capacity, low discharge platform, abundant raw materials and environmental friendliness. However, the large volume changes, unstable solid electrolyte interphase (SEI) formation during cycling and intrinsic low conductivity of Si hinder its practical applications. Various modification strategies have been widely developed to enhance the lithium storage properties of Si−based anodes, including cycling stability and rate capabilities. In this review, recent modification methods to suppress structural collapse and electric conductivity are summarized in terms of structural design, oxide complexing and Si alloys, etc. Moreover, other performance enhancement factors, such as pre−lithiation, surface engineering and binders are briefly discussed. The mechanisms behind the performance enhancement of various Si−based composites characterized by in/ex situ techniques are also reviewed. Finally, we briefly highlight the existing challenges and future development prospects of Si−based anode materials. Full article

The lithium-ion battery (LIB) has become the most widely used electrochemical energy storage device due to the advantage of high energy density. However, because of the low rate of Faradaic process to transfer lithium ions (Li⁺), the LIB has the defects of poor power performance and cycle performance, which can be improved by adding capacitor material to the cathode, and the resulting hybrid device is also known as a lithium-ion battery capacitor (LIBC). This review introduces the typical structure and working principle of an LIBC, and it summarizes the recent research developments in advanced LIBCs. An overview of non-lithiated and pre-lithiated anode materials for LIBCs applications is given, and the commonly used pre-lithiation methods for the anodes of LIBCs are present. Capacitor materials added to the cathodes, and suitable separator materials of LIBCs are also reviewed. In addition, the polarization phenomenon, pulsed performance and safety issues of LIBCs and electrode engineering for improving electrochemical performance are systematically analyzed. Finally, the future research and development direction of advanced LIBCs is prospected through the discussion of the existing problems of an LIBC in which the battery material in the composite cathode is LiNi_xCo_yMn_1−x−yO₂ (NCM). Full article

Using only parts of the maximum capacity of silicon microparticles in a lithium-ion battery (LIB) anode represents a promising material concept. The high capacity, better rate capability compared with graphite and accessibility on an industrial scale, as well as its attractive cost make microsilicon an ideal choice for the next generation anode material. However, currently the cycle life of LIBs using silicon particles in the anode is limited due to drastic volume change of Si during lithiation and delithiation. Continuous formation of a solid electrolyte interphase (SEI) and the associated lithium loss are the main failure mechanisms, while particle decoupling from the conductive network plays a role mainly during operation at low discharge voltages. The present study discusses approaches on the material- and cell-level to enhance cycle performance of partially lithiated silicon microparticle-based full cells by addressing the previously described failure mechanisms. Reducing the surface area of the silicon particles and coating their surface with carbon to improve the electronic contact, as well as prelithiation to compensate for lithium losses have proven to be the most promising approaches. The advantageous combination of these routes resulted in a significant increase in cycling stability exceeding 600 cycles with 80% capacity retention at an initial capacity of about 1000 mAh g⁻¹ at anode level, compared to only about 250 cycles for the non-optimized full cell. Full article

The user demands lithium-ion batteries in mobile applications, and electric vehicles request steady improvement in terms of capacity and cycle life. This study shows one way to compensate for capacity losses due to SEI formation during the first cycles. A fast and simple approach of electrolyte-free direct-contact pre-lithiation leads to targeted degrees of pre-lithiation for graphite electrodes. It uses tailor-made lithium thin films with 1–5 µm lithium films produced by lithium melt deposition as a lithium source. These pre-lithiated graphite electrodes show 6.5% capacity increase after the first cycles in NCM full cells. In this study, the influence of the pre-lithiation parameters—applied pressure, temperature and pressing time—on the pre-lithiation process is examined. Full article

The effects of excessive prelithiation on the full-cell performance of Li-ion batteries (LIBs) with a hard-carbon/nanosized-Si (HC/N-Si) composite anode were investigated; HC and N-Si simply mixed at mass ratios of 9:1 and 8:2 were analyzed. CR2032-type half- and full-cells were assembled to evaluate the electrochemical LIB anode behavior. The galvanostatic measurements of half-cell configurations revealed that the composite anode with an 8:2 HC/N-Si mass ratio exhibited a high capacity (531 mAh g⁻¹) at 0.1 C and superior current-rate dependence (rate performance) at 0.1–10 C. To evaluate the practical LIB anode performance, the optimally performing composite anode was used in the full cell. Prior to full-cell assembly, the composite anodes were prelithiated via electrochemical Li doping at different cutoff anodic specific capacities (200–600 mAh g⁻¹). The composite anode was paired with a LiNi_0.5Co_0.2Mn_0.3O₂ cathode to construct full-cells, the performance of which was evaluated by conducting sequential rate and cycling performance tests. Prelithiation affected only the cycling performance, without affecting the rate performance. Excellent capacity retention was observed in the full-cells with prelithiation conducted at cutoff anodic specific capacities greater than or equal to 500 mAh g⁻¹. Full article

The current mainstream energy storage systems are in urgent need of performance improvements to meet novel application requirements. In pursuit of a higher energy density in Li-ion and Na-ion batteries, the conventional electrode materials have reached the upper limit of their theoretical specific capacities. Hence, facile methods of reducing irreversible lithium-ion/sodium-ion loss are developed to further boost the battery energy density. Herein, we review studies that use polycyclic aromatic hydrocarbons for wet chemical prelithiation and presodiation. The molecular structures of arenes and solvents used for solution-based prelithiation/presodiation have a substantial impact on the prelithiation/presodiation power and effectiveness. Multiple reports have already shown excellent initial Coulombic efficiency and streamlined processes by using this type of wet chemical prelithiation/presodiation strategy. This review article will cover how to select appropriate polycyclic aromatic hydrocarbon prelithiation/presodiation reagents for various materials/electrodes and provide possible directions and guidelines for future works. Full article