Negative Thermal Expansion Material: Promising for Improving Electrochemical Performance and Safety of Lithium-Ion Batteries
Huming Hao, Sheng Xu, Nana Jing, Mengyao Wang, Zhiqiang Wang, Liangxuan Yang, Jianyue Chen, Guan Wang, Guan Wang, Guixin Wang, Guixin Wang
Abstract
Heat and deformation are responsible for poor performance and safety of batteries, but they cannot always be avoided. To address these two issues, ZrW2O8, a negative thermal expansion (NTE) material, was adopted to modify LiNi0.8Co0.1Mn0.1O2 (NCM811) to decline deformation via in situ absorption of the generated heat. The reversible capacity of NCM811 modified with 5 wt % of ZrW2O8 can remain at 180.6 mAh/g after 100 cycles at 60 °C and 1.0 C current rate, which increases the retention ratio of NCM811 by 14.8%, while the voltage difference between main redox peaks, Rct, strain after cycles, and heat from DSC of NCM811 are reduced about 47.8%, 81.0%, 28.2%, and 76.0%, respectively. According to various analysis results, the side reactions are also suppressed, and the enhancing mechanisms of ZrW2O8 for NCM811 were discussed. A general strategy is developed for the management of deformation using heat to improve performance and safety of batteries.