Thermal Energy Evaluation for Rechargeable Lithium Batteries from 300 Wh/kg to 600 Wh/kg

To meet the power demand of long-range electric vehicles (EVs) and electric aviation, rechargeable lithium batteries (RLBs) with cell-level gravimetric energy density (GED) doubling from 300 to 600 Wh/kg have become a research focus in the energy storage field. The key components and materials of a battery (e.g., cathode, anode, and electrolyte) are energetic materials, and batteries with higher electric energy storage capability are usually associated with higher thermal energy release under abuse conditions, which could bring about a higher incidence rate of thermal runaway (TR). In this work, mathematical models were developed for evaluating the total thermal energy (TTE) release during the combustion of rechargeable Li batteries built from different cathode-electrolyte-anode combinations. Results indicate that batteries with a higher energy density do not necessarily pose a higher thermal safety risk. Those batteries built with the layered transition-metal oxide cathode are expected to release less thermal energy than those built with the conversion-type cathode materials such as sulfur, provided with an equal gravimetric energy density, and a similar result is observed by switching from conventional liquid electrolytes (LE) to solid oxide electrolytes. By conducting the research, we aim to offer insights into rational materials design for next-generation batteries with high energy and high safety.