The interface instability between layered oxide cathode and sulfide electrolyte is a key point affecting the perform ance of sulfide-based all-solid-state lithium batteries.Coating with fast-ionic conductor and constr...The interface instability between layered oxide cathode and sulfide electrolyte is a key point affecting the perform ance of sulfide-based all-solid-state lithium batteries.Coating with fast-ionic conductor and constructing core-shell structure can effectively alleviate the interfacial side reactions and improve the interfacial stability between layered oxide and sulfide electrolyte.However,what have been neglected is the surface base(including Li_(2)CO_(3) and LiOH)of layered oxide can also affect the interfacial stability.To clarify this point clearly and improve the interfacial stability,the surface base of LiCoO_(2)(LCO)is regulated and investigated in this work.First,LCO with surface base Li_(2)CO_(3)(LCO@Li_(2)CO_(3))is prepared by the reaction of Co_(3)O_4 and excess Li_(2)CO_(3).Then,the bare LCO is obtained after LCO@Li_(2)CO_(3) is washed with deionized water and calcined again.Besides,LCO with surface base Li_(2)O(LCO@Li_(2)O)is also prepared with the bare LCO and LiOH.As a result,the electrochemical performances of LCO@Li_(2)O are significantly improved and much higher than those of LCO@Li_(2)CO_(3) and the bare LCO electrodes.In particular,LCO@Li_(2)O-2 cathode display the most outstanding electrochemical performances(discharge capacity138.4 mAh·g^(-1)at 0.2C,105 mAh·g^(-1)at 2C and a capacity retention of 95.4%after 150 cycles at 0.5C).The high discharge capacity and excellent cycle stability of LCO@Li_(2)O electrode confirm the effectiveness of regulating the surface base of layered oxide from Li_(2)CO_(3) to Li_(2)O.The surface base regulating is expected to be a simple but effective strategy to construct the stable interface between the cathode and the sulfide electrolyte of the all-solid-state lithium batteries.展开更多
基金financially supported by the National Key Research and Development Program of China (No.2018YFE0111600)the National Natural Science Foundation of China (Nos.52172224 and 22279090)the Science and Technology Major Project of China National Machinery Industry Corporation (No.SINOMAST-ZDZX-2019-04)。
文摘The interface instability between layered oxide cathode and sulfide electrolyte is a key point affecting the perform ance of sulfide-based all-solid-state lithium batteries.Coating with fast-ionic conductor and constructing core-shell structure can effectively alleviate the interfacial side reactions and improve the interfacial stability between layered oxide and sulfide electrolyte.However,what have been neglected is the surface base(including Li_(2)CO_(3) and LiOH)of layered oxide can also affect the interfacial stability.To clarify this point clearly and improve the interfacial stability,the surface base of LiCoO_(2)(LCO)is regulated and investigated in this work.First,LCO with surface base Li_(2)CO_(3)(LCO@Li_(2)CO_(3))is prepared by the reaction of Co_(3)O_4 and excess Li_(2)CO_(3).Then,the bare LCO is obtained after LCO@Li_(2)CO_(3) is washed with deionized water and calcined again.Besides,LCO with surface base Li_(2)O(LCO@Li_(2)O)is also prepared with the bare LCO and LiOH.As a result,the electrochemical performances of LCO@Li_(2)O are significantly improved and much higher than those of LCO@Li_(2)CO_(3) and the bare LCO electrodes.In particular,LCO@Li_(2)O-2 cathode display the most outstanding electrochemical performances(discharge capacity138.4 mAh·g^(-1)at 0.2C,105 mAh·g^(-1)at 2C and a capacity retention of 95.4%after 150 cycles at 0.5C).The high discharge capacity and excellent cycle stability of LCO@Li_(2)O electrode confirm the effectiveness of regulating the surface base of layered oxide from Li_(2)CO_(3) to Li_(2)O.The surface base regulating is expected to be a simple but effective strategy to construct the stable interface between the cathode and the sulfide electrolyte of the all-solid-state lithium batteries.
