Effect of Preload Force on Heat Generation of Li(Ni_(0.8)Co_(0.1)Mn_(0.1))O_(2)/SiO_(x)-C System Batteries:The Discharge Process  

作　　者：LIN Chunjing LAI Zhenxing BAI Guangli MA Biao WEI Zhen QI Chuang LIU Shiqiang 

机构地区：[1]Key Laboratory of Advanced Manufacturing Technology for Automobile Parts,Ministry of Education,Chongqing University of Technology,Chongqing 400054,China [2]China Auto Research New Energy Vehicle Inspection Center(Tianjin)Co,Tianjin 300300,China

出　　处：《Journal of Thermal Science》2024年第5期1809-1825,共17页热科学学报（英文版）

基　　金：the financial supports from the National Key R&D Plan of China(No.2021YFB2402001);the Chongqing Municipal Innovation Project(No.CYS23657)。

摘　　要：Lithium-ion batteries(LIBs)undergo various degradation phenomena such as material decomposition,structural change and uneven lithium ion distribution during long-term cycles,which would affect their performance and safety.In order to improve the performance of the LIBs during their life cycle,preload force is preset when the batteries are assembled.Different preload forces will in turn affect the cycle life and heat generation of the battery.In order to address this issue,this work carries out charge/discharge cycle tests on a NCM811 battery under different preload forces.Isothermal calorimetry tests are performed to investigate the battery heat generation under different states of health(SOHs)and preload forces.Based on the test results,an empirical prediction model for heat generation power as a function of SOH is established.Results show that when the preload force is 5 N·m,the battery capacity decreases in the slowest rate and the average heat generation power is the lowest.Changes in peaks of the incremental capacity curve can be used to characterize the loss of lithium at the electrode,which in turn characterizes the change of heat generation power of the battery.The average heat generation power is mainly affected by the SOH,going through a period of trough with the decrease of the SOH and continuing to increase after crossing the critical point.In general,these findings emphasize the relationship between preload force,SOH and heat generation power,which is helpful for the judgment of optimal preload to improve the efficiency of LIBs.

关 键 词：lithium ion battery cyclic aging preload force heat generation characteristic 

分 类 号：TM912[电气工程—电力电子与电力传动]