Enhanced Electrochemical Performance Of Lini0.6co0.2mn0.2o2 By A Negative-Thermal-Expansion Material At Elevated Temperature

More measures are being developed to enhance the electrochemical stability of single-crystal LiNi0.6Co0.2Mn0.2O2 (NCM622), but few focus on improving the stability of NCM622 through heat and deformation management. Herein, a negative-thermal-expansion (NTE) material of zirconium tungstate ZrW2O8 is adopted to modify NCM622 via a facile method, and the sample with a proper content of ZrW2O8 exhibits superior cycle performance and rate capability. The capacity retention ratio of modified NCM622 is 86.2% (from 193.6 to 166.8 mAh g(-1)) after 100 cycles at 2 C between 2.8 and 4.5 V at 60 degrees C, whereas that of the pristine NCM622 is only 77.5% (from 183.8 to 142.4 mAh g(-1)). According to various analysis results, the possible enhancing mechanisms of ZrW2O8 for NCM622 are discussed. It is an alternative for the remaining good structure of energy materials using NTE materials.