Thermal Runaway Suppression of High-Energy Lithium-Ion Batteries by Designing the Stable Interphase

Battery thermal runaway (TR) hinders the safe application of high-energy lithium-ion batteries with high-nickel cathodes. The use of non-flammable perfluorinated electrolytes is a promising alternative for enhancing the thermal stability of the battery and inhibiting the occurrence of TR. Herein, the electrochemical and thermal performances of single-crystal LiNi0.8Co0.1Mn0.1O2 (SC-NCM811) cathode cells based on a perfluorinated electrolyte were investigated. A conventional electrolyte was selected for comparison. It was found that the capacity of the battery cycling in the perfluorinated electrolyte was as high as 110.12% after 200 cycles. In addition, the test results demonstrate that the perfluorinated electrolyte can increase the trigger temperature of TR by 12.5 °C, decrease the highest temperature of TR by 41.2 °C, and reduce the oxygen release and crack formation. After characterizing the single-crystal cathode in a fully charged state, it can be confirmed that a uniform F, B-rich cathode electrolyte interphase can enhance the battery performance to some extent. This study provides a novel direction for addressing the thermal safety issues of high-nickel lithium-ion batteries.