Implications of the Heat Generation of LMR-NCM on the Thermal Behavior of Large-Format Lithium-Ion Batteries

Lithium- and manganese-rich NCM (LMR-NCM) cathode active materials exhibit a pronounced energy inefficiency during charge discharge that results in strong heat generation operation. The implications of such are investigated for large-format lithium-ion batteries. Small laboratory cells generally considered isothermal, but larger cell formats this cannot be neglected. Therefore, the LMR-NCM/graphite coin NCA/graphite as reference is measured varying charge/discharge rates an isothermal flow calorimeter scaled to standardized formats. With aid thermal 3D models, temperature evolution within these under different operations cooling conditions analyzed. Without additional sink any cells, C-rates lower than C/2 advisable keep below critical threshold. If loads increased, strategy has adapted specific format, otherwise temperatures above 60 °C easily reached. For convective surface base plate scenarios, thick prismatic with LMR-NCM unfavorable, large amount adequately dissipated.