Simultaneously adjusting deformation and heat using a negative thermal expansion material to enhance electrochemical performance and safety of lithium-ion batteries

Heat and deformation are extremely significant for battery performance and safety, and LiNi0.85Co0.13Al0.02O2 (NCA) is attractive for high energy density. Herein, the deformation of NCA was effectively controlled by in situ removing the generated heat using a negative thermal expansion (NTE) material of ZrW2O8. The acceleration of ZrW2O8 for NCA becomes more obvious under extreme conditions like elevated current densities and temperature. The discharge specific capacity of NZ5 reaches 162.1 mAh/g at 5.0C, and remains at 150.1 mAh/g after 100 cycles at 1.0C, 36.2 mAh/g higher than that of NCA. As temperature increases to 60 degrees C, the capacity of NZ(5) remains at 160.2 mAh/g after 100 cycles, 20.2% improvement of NCA. The strain value of NZ(5) after cycles is 66.3 mu epsilon, much lower than 103.3 mu epsilon of NCA. Simultaneously, ZrW2O8 declines the heat of NCA from 29.7 to 2.0 J g(-1), so does side reactions. Combining abundant results, ZrW2O8 enhancing mechanisms for NCA were discussed. The findings do matter to perfecting energy materials by simultaneously adjusting deformation and interface using heat.