采用共沉淀高温固相反应法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(811),通过掺入Li、Mg和Al元素,并采用SEM、XRD、电化学测试,研究掺杂对材料晶体结构和电化学性能影响规律.实验结果表明:共沉淀过程中三价金属离子(Mn^(...采用共沉淀高温固相反应法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(811),通过掺入Li、Mg和Al元素,并采用SEM、XRD、电化学测试,研究掺杂对材料晶体结构和电化学性能影响规律.实验结果表明:共沉淀过程中三价金属离子(Mn^(3+)、Al^(3+))出现会促使少量α-Ni(OH)2形成,而Li^+、Mg^(2+)和Al^(3+)均溶入晶格无杂相析出.高温融锂反应中,三种掺杂元素显著削弱Ni^(2+)出现数量,抑制Ni^(2+)混排进入Li^+格位,大幅提升811基体可逆容量;Mg^(2+)、Al^(3+)掺杂进一步增强基体晶格稳定性,改善其循环性能;Li^+-Al^(3+)共掺杂使之达到最佳:首次充电效率ICE超过90%,0.2C倍率下50次循环容量达195.8 m Ah/g、容量保持率为96.2%.展开更多
Owing to the high specific capacity and high voltage,Ni-rich(LiNi0.8Co0.1Mn0.1O2,LNCM811)cathode has been considered as one of the most promising candidate cathode materials for next generation lithium ion batteries,w...Owing to the high specific capacity and high voltage,Ni-rich(LiNi0.8Co0.1Mn0.1O2,LNCM811)cathode has been considered as one of the most promising candidate cathode materials for next generation lithium ion batteries,whereas severe capacity fading greatly hinders its practical application.Notably,the compatibility of Ni-rich materials with LiBF4-containing electrolyte has not yet been realized.Herein,1 M LiPF6-based electrolyte with introducing 2 M LiBF4 is proposed to dramatically improve the cyclic stability of high voltage LNCM811/Li half-cell.Addition of high concentrated LiBF4 improves the moisture stability of electrolyte,which hinders the generation of harmful by-product HF,resulting in improved interfacial stability of LNCM811.Lithium plating/stripping reaction of Li/Li symmetric cell confirms that the enhanced cyclic stability is ascribed to the improved interfacial stability of LNCM811 instead of lithium electrode.Morphology and composition characterization results reveal that LiBF4 participates in the CEI film-forming reaction,resulting in suppressed oxidation of electrolyte and interfacial structural destruction of LNCM811.展开更多
In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium ...In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium batteries(ASSLB)using sulfide solid electrolyte.However,the electrochemical performances are still not satisfactory,due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode,especially Ni-rich oxide cathodes,in charge-discharge process.Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg^-1 in liquid LIB,but rarely investigated in ASSLB using sulfide electrolyte.To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary.In this work,in view of our previous work,LiNbO3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li10GeP2S12 solid electrolyte.Consequently,LiNbO3-coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.展开更多
Sulfide all-solid-state lithium batteries(SASSLBs)with a single-crystal nickel-rich layered oxide cathode(LiNix-CoyMn_(1-x-y)O_(2),x≥0.8)are highly desirable for advanced power batteries owing to their excellent ener...Sulfide all-solid-state lithium batteries(SASSLBs)with a single-crystal nickel-rich layered oxide cathode(LiNix-CoyMn_(1-x-y)O_(2),x≥0.8)are highly desirable for advanced power batteries owing to their excellent energy density and safety.Nevertheless,the cathode material's cracking issue and its severe interfacial problem with sulfide solid electrolytes have hindered the further development.This study proposes to employ surface modification engineering to produce B-NCM cathode materials coated with boride nanostructure stabilizer in situ by utilizing NCM encapsulated with residual lithium.This approach enhances the electrochemical performance of SASSLBs by effectively inhibiting electrochemical-mechanical degradation of the NCM cathode material on cycling and reducing deleterious side reactions with the solid sulfide electrolyte.The B-NCM/LPSCl/Gr SASSLBs demonstrate impressive cycling stability,retaining 84.19%of its capacity after 500 cycles at 0.2 C,which represents a 30.13%increase vs.NCM/LPSCl/Gr.It also exhibits a specific capacity of 170.4 mAh/g during its first discharge at 0.1 C.This work demonstrates an effective surface engineering strategy for enhancing capacity and cycle life,providing valuable insights into solving interfacial problems in SASSLBs.展开更多
文摘采用共沉淀高温固相反应法合成锂离子电池正极材料LiNi_(0.8)Co_(0.1)Mn_(0.1)O_2(811),通过掺入Li、Mg和Al元素,并采用SEM、XRD、电化学测试,研究掺杂对材料晶体结构和电化学性能影响规律.实验结果表明:共沉淀过程中三价金属离子(Mn^(3+)、Al^(3+))出现会促使少量α-Ni(OH)2形成,而Li^+、Mg^(2+)和Al^(3+)均溶入晶格无杂相析出.高温融锂反应中,三种掺杂元素显著削弱Ni^(2+)出现数量,抑制Ni^(2+)混排进入Li^+格位,大幅提升811基体可逆容量;Mg^(2+)、Al^(3+)掺杂进一步增强基体晶格稳定性,改善其循环性能;Li^+-Al^(3+)共掺杂使之达到最佳:首次充电效率ICE超过90%,0.2C倍率下50次循环容量达195.8 m Ah/g、容量保持率为96.2%.
基金supported by the National Natural Science Foundation of China(21573080)the Guangdong Program for Support of Top-notch Young Professionals(2015TQ01N870)+1 种基金Distinguished Young Scholar(2017B030306013)the Science and Technology Planning Project of Guangdong Province(Grant no.2017B090901020)
文摘Owing to the high specific capacity and high voltage,Ni-rich(LiNi0.8Co0.1Mn0.1O2,LNCM811)cathode has been considered as one of the most promising candidate cathode materials for next generation lithium ion batteries,whereas severe capacity fading greatly hinders its practical application.Notably,the compatibility of Ni-rich materials with LiBF4-containing electrolyte has not yet been realized.Herein,1 M LiPF6-based electrolyte with introducing 2 M LiBF4 is proposed to dramatically improve the cyclic stability of high voltage LNCM811/Li half-cell.Addition of high concentrated LiBF4 improves the moisture stability of electrolyte,which hinders the generation of harmful by-product HF,resulting in improved interfacial stability of LNCM811.Lithium plating/stripping reaction of Li/Li symmetric cell confirms that the enhanced cyclic stability is ascribed to the improved interfacial stability of LNCM811 instead of lithium electrode.Morphology and composition characterization results reveal that LiBF4 participates in the CEI film-forming reaction,resulting in suppressed oxidation of electrolyte and interfacial structural destruction of LNCM811.
基金financially supported partly by the National Key Research and Development Program of China (2018YFB0104302)NSFC (21503148)Major Programs of the Innovation Driven Plan of Guilin (No. 20160203)
文摘In order to obtain high power density,energy density and safe energy storage lithium ion batteries(LIB)to meet growing demand for electronic products,oxide cathodes have been widely explored in all-solidstate lithium batteries(ASSLB)using sulfide solid electrolyte.However,the electrochemical performances are still not satisfactory,due to the high interfacial resistance caused by severe interfacial instability between sulfide solid electrolyte and oxide cathode,especially Ni-rich oxide cathodes,in charge-discharge process.Ni-rich LiNi0.8Co0.1Mn0.1O2(NCM811)material at present is one of the most key cathode candidates to achieve the high energy density up to 300 Wh kg^-1 in liquid LIB,but rarely investigated in ASSLB using sulfide electrolyte.To design the stable interface between NCM811 and sulfide electrolyte should be extremely necessary.In this work,in view of our previous work,LiNbO3 coating with about 1 wt% content is adopted to improve the interfacial stability and the electrochemical performances of NCM811 cathode in ASSLB using Li10GeP2S12 solid electrolyte.Consequently,LiNbO3-coated NCM811 cathode displays the higher discharge capacity and rate performance than the reported oxide electrodes in ASSLB using sulfide solid electrolyte to our knowledge.
基金support from the National Natural Science Foundation of China(Grant No.52374407)is gratefully acknowledged.
文摘Sulfide all-solid-state lithium batteries(SASSLBs)with a single-crystal nickel-rich layered oxide cathode(LiNix-CoyMn_(1-x-y)O_(2),x≥0.8)are highly desirable for advanced power batteries owing to their excellent energy density and safety.Nevertheless,the cathode material's cracking issue and its severe interfacial problem with sulfide solid electrolytes have hindered the further development.This study proposes to employ surface modification engineering to produce B-NCM cathode materials coated with boride nanostructure stabilizer in situ by utilizing NCM encapsulated with residual lithium.This approach enhances the electrochemical performance of SASSLBs by effectively inhibiting electrochemical-mechanical degradation of the NCM cathode material on cycling and reducing deleterious side reactions with the solid sulfide electrolyte.The B-NCM/LPSCl/Gr SASSLBs demonstrate impressive cycling stability,retaining 84.19%of its capacity after 500 cycles at 0.2 C,which represents a 30.13%increase vs.NCM/LPSCl/Gr.It also exhibits a specific capacity of 170.4 mAh/g during its first discharge at 0.1 C.This work demonstrates an effective surface engineering strategy for enhancing capacity and cycle life,providing valuable insights into solving interfacial problems in SASSLBs.
