All-solid-state lithium batteries(ASSLBs)based on sulfide electrolytes promise next-generation energy storage with high energy density and safety.However,the sulfide electrolytes suffer from phase instability and slug...All-solid-state lithium batteries(ASSLBs)based on sulfide electrolytes promise next-generation energy storage with high energy density and safety.However,the sulfide electrolytes suffer from phase instability and sluggish interfacial charge transport when pairing with layered oxide cathodes at high voltages.Herein,a simple and efficient strategy is proposed using two-dimensional Ti_(3)C_(2)T_(x)MXene as starting material to in-situ construct a 15 nm Li_(2)TiO_(3) layer on a typical oxide cathode,LiCoO_(2).The in-situ transformation of Ti_(3)C_(2)T_(x)into Li_(2)TiO_(3) layer occurs at a low temperature of 500℃,avoiding the phase deterioration of LiCoO_(2).The thin Li_(2)TiO_(3) layer is Li^(+)conducting and electrochemically stable,thereby preventing the interfacial decomposition of sulfide electrolytes induced by LiCoO_(2) at high voltages and facilitating Li+transport at the interface.Moreover,Li_(2)TiO_(3) can stabilize the layer structure of LiCoO_(2) at high voltages.Consequently,the sulfide-based ASSLB using LiCoO_(2)@Li_(2)TiO_(3) cathode can operate stably at a high voltage of up to 4.5 V(vs.Li+/Li),delivering an outstanding initial specific discharge capacity of 138.8 m Ah/g with a high capacity retention of 86.2% after 100 cycles at 0.2 C.The in-situ transformation strategy may also apply to other MXenes,offering a general approach for constructing other advanced lithiated coatings for oxide cathodes.展开更多
基金the financial support from the National Natural Science Foundation of China(Nos.52201242,52250010)Natural Science Foundation of Jiangsu Province(Nos.BK20200386,BK20200186)+1 种基金Young Elite Scientists Sponsorship Program by CAST(No.2021QNRC001)the Fundamental Research Funds for the Central Universities(No.2242022R40018)。
文摘All-solid-state lithium batteries(ASSLBs)based on sulfide electrolytes promise next-generation energy storage with high energy density and safety.However,the sulfide electrolytes suffer from phase instability and sluggish interfacial charge transport when pairing with layered oxide cathodes at high voltages.Herein,a simple and efficient strategy is proposed using two-dimensional Ti_(3)C_(2)T_(x)MXene as starting material to in-situ construct a 15 nm Li_(2)TiO_(3) layer on a typical oxide cathode,LiCoO_(2).The in-situ transformation of Ti_(3)C_(2)T_(x)into Li_(2)TiO_(3) layer occurs at a low temperature of 500℃,avoiding the phase deterioration of LiCoO_(2).The thin Li_(2)TiO_(3) layer is Li^(+)conducting and electrochemically stable,thereby preventing the interfacial decomposition of sulfide electrolytes induced by LiCoO_(2) at high voltages and facilitating Li+transport at the interface.Moreover,Li_(2)TiO_(3) can stabilize the layer structure of LiCoO_(2) at high voltages.Consequently,the sulfide-based ASSLB using LiCoO_(2)@Li_(2)TiO_(3) cathode can operate stably at a high voltage of up to 4.5 V(vs.Li+/Li),delivering an outstanding initial specific discharge capacity of 138.8 m Ah/g with a high capacity retention of 86.2% after 100 cycles at 0.2 C.The in-situ transformation strategy may also apply to other MXenes,offering a general approach for constructing other advanced lithiated coatings for oxide cathodes.
