Reversible Low Temperature Li-Storage In Liquid Metal Based Anodes Via A Co-Solvent Strategy(Dagger)

Main observation and conclusion The application of lithium-ion batteries in cold climates has been hindered due to the decline in performance at low temperatures. The increased de-solvation energy and formation of Li dendrites at the anode surface emerge as the major challenges, which rely on the development of stable anode and compatible electrolytes. Herein, a self-healing GaInSn liquid metal (LM) based electrode coupled with a multi-solvent electrolyte is proposed toward reversible Li-storage at low temperatures. By using methyl butyrate (MB) as a co-solvent in 1 mol center dot L-1 LiTFSI of ethylene carbonate and diethyl carbonate, the electrolyte viscosity decreases from 52.07 to 13.75 mPa center dot s, while the ionic conductivity increases from 1.38 to 3.44 mS center dot cm(-1) at -20 degrees C. Moreover, the Li/MXene@LM cells can display a discharge capacity of 500 mAh center dot g(-1), with capacity retention of 78% at -20 degrees C after 120 cycles. It is disclosed that a uniform LiF-rich solid electrolyte interface (SEI) layer on the anode is formed upon the addition of MB, which promotes the desolvation of Li ions at the interface of electrode/electrolyte especially at low temperatures. These results prove that MB as the co-solvent is well compatible with LM based anodes and holds great potential for the exploration of low-temperature energy devices.