From-20 Degrees C To 150 Degrees C: A Lithium Secondary Battery With A Wide Temperature Window Obtained Via Manipulated Competitive Decomposition In Electrolyte Solution Dagger

Lithium secondary batteries (LSBs) have witnessed explosive growth in the last decade. A wide operating temperature window is crucial for practical applications. A new concept is developed to expand the temperature window between -20 degrees C and 150 degrees C, where a competitive decomposition process between the electrolyte and solvent is manipulated with adiponitrile (ADN) over a wide temperature range. The decomposition of ethylene carbonate (EC) solvent and anions of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium oxalyldifluoroborate (LiODFB) is regulated with ADN via a temperature-dependent lithium solvation mechanism. As a result, a SEI layer with a rich inorganic component is formed at elevated temperatures, leading to improved performance in lithium titanate (LTO)/Li, lithium iron phosphate (LFP)/Li, and LiNi0.5Co0.2Mn0.3O2 (NCM523)/Li batteries over a wide temperature range. It enables a coulombic efficiency (CE) of 97.39% at 100 degrees C and more than 100 hours of cycling of Li/Li batteries at 150 degrees C, as well as stable cycling of LFP/Li batteries in the temperature range between 120 degrees C and -20 degrees C. Stable cycling performance is demonstrated with the LTO/Li batteries over a wider temperature range from -40 degrees C to 150 degrees C. High-temperature electrochemical stability is exhibited at 5C, with a capacity retention ratio of 87.94% at 120 degrees C and 99.93% at 100 degrees C after 1000 cycles.