**1. Introduction**

Air pollution and global climate change are fundamental issues for today's society. New technological innovations are necessary to overcome these problems. Considerable eco-friendly changes have to be made for principal way of transport, which is mostly based on the internal combustion engine. One of the possibilities to have cleaner environment is the electrification of buses, cars, and trucks.

The applications of lithium-ion batteries are increasing in di fferent sectors, such as space and automotive industries and consumer electronics to meet the power and energy requirements [1]. Notwithstanding, understanding a battery's rate of useful life or capacity loss in these applications is necessary, especially in automotive and space industry. In addition, determining the durability and performance of the lithium-ion batteries are critical [1].

Li-ion batteries have so many applications in di fferent sectors. One of the problems related to these batteries is their lifetime. Their lifetime is not limitless, and they have a restricted lifetime due to some limitations in technology.

It is possible to expand their market by increasing their cycle life. In the past few years, substantial efforts have been accomplished for model development and to anticipate capacity fade in lithium ion batteries [1–3]. Notwithstanding, experimental data are necessary for the investigation of the capacity fading mechanisms and the aging processes of a battery system [1].

A factor influencing the rechargeable capacity of a lithium-ion battery cell was described [4]. It was seen that diminution resistive electrolytes and oxidation are essential to improve the discharge and charge coulombic e fficiencies of both the negative and positive electrodes [4]. It was concluded that electrochemical investigations on the diminution of electrolytes and oxidation, accompanied with the chemical investigation of reaction products, would assistance anticipation in safety and advance cycle life for a lithium-ion cell [4].

Testing life cycle under many cycles such as fifteen thousand cycles and undergoing situation that simulate real application is significantly problematic due to the testing time, which is an extraordinarily long time. The capacity retention plays an important role in the lifetime of Li-ion batteries.

According to the data that were assembled from the cycle life experiments of two kinds of commercial lithium-ion battery cells containing NMC battery cells and LFP battery cells, which were experimentally studied the long-term coulombic e fficiency development and its correspondence with the battery cell degradation. The findings demonstrate that NMC and LFP cells display two di fferent aging behaviors [5].

A semi-empirical model that was obtained from the correspondence among battery degradation and coulombic e fficiency was suggested to seize the capacity degradation behavior of several cylindrical lithium-ion batteries [6]. The suggested model seizes the convexity of the degradation arc competently, exhibits a superior goodness-of-fit than the generally employed square-root-of time model. In addition, it introduces an extreme robustness versus simulated data, with dissimilar aging shapes [6].

Coulombic e fficiency and continuous-time energy e fficiency of several lithium titanate batteries were investigated according to dissimilar discharge current rates and state of charge sections. The experimental outcomes demonstrated the coulombic e fficiency and energy e fficiency discrepancy in dissimilar state of charge sections and changing discharge rates [7].

Di fferent investigations regarding the coulombic e fficiency of lithium-ion batteries have been done. Notwithstanding, e ffect of di fferent prior cycling and current rates on the coulombic e fficiency of lithium-ion batteries were not precisely and comprehensively studied. Therefore, the main objective of this investigation was to determine the impact of important parameters such as current rate and prior cycling on the coulombic e fficiency of the battery cell by accomplishing di fferent experiments.

Although many investigations about discharge and charge processes on lithium-ion batteries have been accomplished [8,9] most of them were accomplished by applying discharging and charging for di fferent current rates. In this investigation, a comprehensive investigation of discharge and charge parameters of a lithium-ion battery was demonstrated. The coulombic e fficiency of the lithium-ion battery at di fferent current rates was determined. In addition, dependence and impact of the discharging and charging intensity, on the coulombic e fficiency of the battery cell was studied.
