Journal of Energy Chemistry ( IF 13.1 ) Pub Date : 2020-06-19 , DOI: 10.1016/j.jechem.2020.06.008 Chen Liang , Lihua Jiang , Shuliang Ye , Zhaoyu Wang , Zesen Wei , Qingsong Wang , Jinhua Sun
Multiple mode calorimetry and C80 micro-calorimeter are used to investigate the impact of cathode and anode on heat generation of lithium ion battery. The thermal behaviors of LiNixCoyMnzO2/graphite full cell are discussed under normal operating and elevating temperature. Affected by negative entropy change, lithium intercalation presents more exotherms than deintercalation for both electrode materials. The contributions of irreversible and reversible heat to the total heat generation of graphite are evaluated. The phase transitions correlated with voltages and lithium contents are determined. Based on the analysis of half-cell, the effect of two electrodes (with the same capacity) on overall heat generation is nearly the same and anode of full cell plays a key role in charging while cathode dominates in discharging. Thermal behaviors of lithiated graphite and delithiated LiNixCoyMnzO2, electrolyte and their coexisting system are identified to further explore their influence on battery safety. The breakdown of solid electrolyte interface (SEI) at around 82 °C is considered as a crucial factor affecting the thermal stability of full cell. The oxidation of electrolyte induced by oxygen released from cathode material turns out to be one of the main heat sources. These accurate results are of great significance to improve the existing thermal management system and provide basic data for the prediction of battery performance.
中文翻译:
LiNi 1/3 Co 1/3 Mn 1/3 O 2 /石墨纽扣电池热行为的精确原位和异位研究:从部分到整个单元
采用多模式量热法和C80微量量热仪研究了正极和负极对锂离子电池发热的影响。LiNi x Co y Mn z O 2的热行为/石墨全晶胞在正常工作和升高温度下进行了讨论。受负熵变化的影响,两种电极材料的锂嵌入均比脱嵌呈现更多的放热。评估了不可逆和可逆热对石墨总热量的贡献。确定与电压和锂含量相关的相变。根据半电池的分析,两个电极(容量相同)对整体发热的影响几乎相同,而全电池的阳极在充电中起关键作用,而阴极在放电中起主要作用。锂化石墨和去锂化LiNi x Co y Mn z O 2的热行为确定了电解质及其共存体系,以进一步探索它们对电池安全性的影响。固态电解质界面(SEI)在82°C左右的击穿被认为是影响整个电池的热稳定性的关键因素。由阴极材料释放的氧气引起的电解质氧化被证明是主要的热源之一。这些准确的结果对于改善现有的热管理系统和为预测电池性能提供基础数据具有重要意义。