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 d...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·L^(–1)LiTFSI of ethylene carbonate and diethyl carbonate,the electrolyte viscosity decreases from 52.07 to 13.75 mPa·s,while the ionic conductivity increases from 1.38 to 3.44 mS·cm^(–1)at–20°C.Moreover,the Li/MXene@LM cells can display a discharge capacity of 500 mAh·g^(–1),with capacity retention of 78%at–20°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.展开更多
基金supported by the National Key Research and Development Program of China(2018YFE0124500 and 2019YFA0705700)the National Natural Science Fund for Distinguished Young Scholars(51825102)+1 种基金the National Natural Science Foundation of China(U1804255)open funding of Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education,Harbin Engineering University.
文摘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·L^(–1)LiTFSI of ethylene carbonate and diethyl carbonate,the electrolyte viscosity decreases from 52.07 to 13.75 mPa·s,while the ionic conductivity increases from 1.38 to 3.44 mS·cm^(–1)at–20°C.Moreover,the Li/MXene@LM cells can display a discharge capacity of 500 mAh·g^(–1),with capacity retention of 78%at–20°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.
