Degradation and Thermal Characteristics of LiNi_0.8Co_0.15Al_0.05O₂/Graphite Lithium Ion Battery after Different State of Charge Ranges Cycling

Authors

Cun WANG, 1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;
Wei-jiang ZHANG, 1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;5. University of Chinese Academy of Sciences, Beijing 100049;
Teng-fei HE, 1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;
Bo LEI, 2. State Key Laboratory of HVDC, Electric Power Research Institute, China Southern Power Grid, Guangzhou 510063;
You-jie SHI, 2. State Key Laboratory of HVDC, Electric Power Research Institute, China Southern Power Grid, Guangzhou 510063;
Yao-dong ZHENG, 3. China Southern Power Grid,Guangzhou 510063;
Wei-lin LUO, 4. Shanghai Power& Energy Storage Battery System Engineering Technology Co. Ltd., Shanghai 200241;
Fang-ming JIANG, 1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;Follow

Corresponding Author

Fang-ming JIANG(jiangfm@ms.giec.ac.cn)

Abstract

The LiNi_0.8Co_0.15Al_0.05O₂ (NCA) cathode exhibits high energy density and large reversible capacity, which plays an essential role in the field of electric vehicles (EVs). However, low capacity retention and poor thermal stability limit its application. Few literatures are found for the capacity degradation mechanism of NCA/graphite batteries at home and abroad. The different state of charge (SOC) ranges cycle degradation behaviors of 18650-type NCA/graphite (2.4 Ah) battery were studied in this paper. The SOC ranges considered were 0% ~ 20% (low), 20% ~ 70% (medium), 70% ~ 100% (high), and 0% ~ 100% (whole). To obtain the states of the batteries being cycled in different SOC ranges, the basic characteristics of the four batteries, including capacity, incremental capacity (IC), internal resistance, and electrochemical impedance spectroscopy (EIS), were tested at 25 ^oC before and after every 100-cycle up to 400 cycles. At the same time, the surface temperature of the batteries during discharging was monitored to analyze the thermal characteristics. A detailed analysis for the IC curve of NCA/graphite was performed, making the mechanism of capacity degradation more clear. The results show that the battery life would be shortened after the whole SOC range cycling and the battery aging rate would be reduced to a certain extent upon cycled in the partial range. In addition, the battery thermal characteristic became the worst after the whole SOC range cycling, but the battery thermal performance became the best after the medium SOC range cycling. Analyzing IC data reveals that the main reason for the performance degradation of batteries in the high, medium and low SOC ranges cycling may be the loss of active lithium ions, and that in the high SOC range cycling may also include the loss of active materials and the increase of reaction internal resistance.

Graphical Abstract

Keywords

Key Words: lithium ion battery, nickel-cobalt-aluminum ternary cathode material, cycle interval, incremental capacity analysis, electrochemical impedance spectroscopy, degradation mechanism

DOI Link

https://doi.org/10.13208/j.electrochem.200507

Publication Date

2020-12-28

Online Available Date

2020-06-15

Revised Date

2020-06-12

Received Date

2020-05-07

Recommended Citation

Cun WANG, Wei-jiang ZHANG, Teng-fei HE, Bo LEI, You-jie SHI, Yao-dong ZHENG, Wei-lin LUO, Fang-ming JIANG. Degradation and Thermal Characteristics of LiNi_0.8Co_0.15Al_0.05O₂/Graphite Lithium Ion Battery after Different State of Charge Ranges Cycling[J]. Journal of Electrochemistry, 2020 , 26(6): 777-788.
DOI: 10.13208/j.electrochem.200507
Available at: https://jelectrochem.xmu.edu.cn/journal/vol26/iss6/1