Thermal Management Strategies for High-Energy-Density Lithium-Ion Batteries in EV system

Against the backdrop of the global energy structure accelerating its transition towards clean energy, the electric vehicle (EV) industry has experienced explosive growth. Lithium-ion batteries (LIBs), with their core advantages of renewability and environmental friendliness, have been widely used for EVs. To further enhance the driving range and lightweight design of EVs, nickel-cobalt-manganese ternary (NCM) batteries have been commercially adopted due to their high energy density and long cycle life. However, current research reveals constraints in NCM battery development: high cost of cobalt (accounting for 40% of battery cost) and low thermal stability of materials like Li[Ni.Co.Mn.]O (NCM811), which easily triggers thermal runaway with severe consequences. This review analyzes the process and mechanism of thermal runaway in the NCM811 system. Studies indicate that the intense exothermic reactions during thermal runaway are caused by oxygen released from redox reactions of the anode and cathode at elevated temperatures. To further improve energy density and mitigate potential thermal runaway risks, this study discusses advanced anode materials and solid-state electrolyte modifications for the NCM811 system, compares the advantages and disadvantages of traditional materials, and reviews novel battery cooling systems and thermal simulation models.