Performance and Life Degradation Characteristics Analysis of NCM LIB for BESS

Abstract

The battery energy storage system (BESS) market is growing rapidly around the world. Lithium Nickel Cobalt Manganese Oxide (LiNiCoMnO2) is attracting attention due to its excellent energy density, high output power, and fast response characteristics. It is being extensively researched and is finding use in many applications, such as in electric vehicles (EV) and energy storage systems (ESS). The performance and lifetime characteristics of a battery change for varying Ni contents. The consideration of these characteristics of a battery allow for a more reliable battery management system (BMS) design. In this study, various experiments and analyses were carried out using a lithium-ion battery (NCM LIB) with differing Ni contents. In particular, the following two combinations were studied: LiNi0.5Co0.2Mn0.3O2(NCM523) and LiNi0.6Co0.2Mn0.2O2 (NCM622). Various analyses were performed, such as C-rate (C-rate is the charge-discharge rate of a battery relative to nominal capacity) performance tests, hybrid pulse power characterization (HPPC), accelerated deterioration experiments, electrochemical impedance spectroscopy (EIS), parameter estimations of battery equivalent circuits through alternating current (AC) and direct current (DC) impedance, and comparative analyses of battery modeling.