High-capacity anode materials,such as SiO and Si/C,are considered promising candidates for high-energydensity lithium-ion batteries.However,the low initial Coulombic efficiency of these anode materials induced by side...High-capacity anode materials,such as SiO and Si/C,are considered promising candidates for high-energydensity lithium-ion batteries.However,the low initial Coulombic efficiency of these anode materials induced by side reactions(forming Li_(2)O and lithium silicate)and the formation of solid electrolyte interface film reduces the active Liions and causes low-discharge capacity.Adding a Li-compensation material in the cathode or anode is an effective strategy to overcome this problem.The most used Li-compensation material is the stabilized lithium metal powder.However,this strategy has high safety risks,high costs,and is challenging to quantify.Herein,the Li-compensation material of Li_(6)CoO_(4) is synthesized and investigated.The preparation conditions,stability in the air,delithiation mechanism,and structural transformation are analyzed and discussed.Electrochemical tests reveal that the discharge capacity and capacity retention of the full pouch cells(3-Ah)with Li_(6)CoO_(4) additive is significantly improved.Also,the reason for such improvement is investigated.This work provides an effective strategy of Li-compensating technology to enhance the electrochemical performance of lithium-ion batteries.展开更多
基金supported by the National Key R&D Program of China(2016YFB0100500)the Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2017-05)。
文摘High-capacity anode materials,such as SiO and Si/C,are considered promising candidates for high-energydensity lithium-ion batteries.However,the low initial Coulombic efficiency of these anode materials induced by side reactions(forming Li_(2)O and lithium silicate)and the formation of solid electrolyte interface film reduces the active Liions and causes low-discharge capacity.Adding a Li-compensation material in the cathode or anode is an effective strategy to overcome this problem.The most used Li-compensation material is the stabilized lithium metal powder.However,this strategy has high safety risks,high costs,and is challenging to quantify.Herein,the Li-compensation material of Li_(6)CoO_(4) is synthesized and investigated.The preparation conditions,stability in the air,delithiation mechanism,and structural transformation are analyzed and discussed.Electrochemical tests reveal that the discharge capacity and capacity retention of the full pouch cells(3-Ah)with Li_(6)CoO_(4) additive is significantly improved.Also,the reason for such improvement is investigated.This work provides an effective strategy of Li-compensating technology to enhance the electrochemical performance of lithium-ion batteries.
