采用草酸盐共沉淀法制备了一系列(x=0.1、0.2、0.3、0.4、0.5)异质结构的尖晶石/层状复合正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电...采用草酸盐共沉淀法制备了一系列(x=0.1、0.2、0.3、0.4、0.5)异质结构的尖晶石/层状复合正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电流充放电测试等表征手段对材料的晶体结构、微观形貌和电化学性能进行了系统研究。结果表明,x=0.2的材料具有最佳的高倍率性能和长循环稳定性。在2.7~4.5 V,1C下循环100次后(1 C=180 m A?g^(-1)),放电比容量为144 m Ah?g-1,容量保持率为92%;在10 C时的放电比容量仍能达到126 m Ah?g^(-1),相比于原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料的放电比容量(73 m Ah?g^(-1))有较大提高。此外,该材料的储能能力也非常突出,在0.1和10 C时的比能量密度分别为733.44和437.21 W×h?kg^(-1)。展开更多
The oxygen evolution behavior in overcharged LiNil/3COl/3Mnl/3Oz-based electrode was investigated by differ- ential scanning calorimetry and thermal gravimetric （DSC/TG）. Meantime, its thermal kinetic parameters wer...The oxygen evolution behavior in overcharged LiNil/3COl/3Mnl/3Oz-based electrode was investigated by differ- ential scanning calorimetry and thermal gravimetric （DSC/TG）. Meantime, its thermal kinetic parameters were calculated by Kissinger＇s and Ozawa＇s method. As observed by DSC/TG, two exothermic peaks at 239 and 313℃ in washed cathode （4.6 V）, were attributed to two steps of oxygen evolution. More importantly, the temperature of its oxygen release processes decreased obviously compared with that charged to 2.8 V. Activation energy （E） for the first and second oxygen evolution, both of which were assumed closely to be the first order reaction, between 200 and 350℃ in Lio.2o4NilnCol/3Mnl/3O2-based electrode were calculated as 113.63 and 158.13 kJ.mo1-1, respectively and the corresponding Arrhenius pre-exponential factors （A） of 1.05 × 10^11 and 6.46× 10^13 s-1 were also obtained. The different energy barrier of such two steps of oxygen evolution should probably be ascribed to the different bond energy of M--O （M=Mn, Co, Ni）.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
文摘采用草酸盐共沉淀法制备了一系列(x=0.1、0.2、0.3、0.4、0.5)异质结构的尖晶石/层状复合正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电流充放电测试等表征手段对材料的晶体结构、微观形貌和电化学性能进行了系统研究。结果表明,x=0.2的材料具有最佳的高倍率性能和长循环稳定性。在2.7~4.5 V,1C下循环100次后(1 C=180 m A?g^(-1)),放电比容量为144 m Ah?g-1,容量保持率为92%;在10 C时的放电比容量仍能达到126 m Ah?g^(-1),相比于原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料的放电比容量(73 m Ah?g^(-1))有较大提高。此外,该材料的储能能力也非常突出,在0.1和10 C时的比能量密度分别为733.44和437.21 W×h?kg^(-1)。
基金Project supported by the National Natural Science Foundation of China （No. 50542004） and Graduate Degree Thesis Innovation Foundation of Central South University （No. 1960-71131100017）.
文摘The oxygen evolution behavior in overcharged LiNil/3COl/3Mnl/3Oz-based electrode was investigated by differ- ential scanning calorimetry and thermal gravimetric （DSC/TG）. Meantime, its thermal kinetic parameters were calculated by Kissinger＇s and Ozawa＇s method. As observed by DSC/TG, two exothermic peaks at 239 and 313℃ in washed cathode （4.6 V）, were attributed to two steps of oxygen evolution. More importantly, the temperature of its oxygen release processes decreased obviously compared with that charged to 2.8 V. Activation energy （E） for the first and second oxygen evolution, both of which were assumed closely to be the first order reaction, between 200 and 350℃ in Lio.2o4NilnCol/3Mnl/3O2-based electrode were calculated as 113.63 and 158.13 kJ.mo1-1, respectively and the corresponding Arrhenius pre-exponential factors （A） of 1.05 × 10^11 and 6.46× 10^13 s-1 were also obtained. The different energy barrier of such two steps of oxygen evolution should probably be ascribed to the different bond energy of M--O （M=Mn, Co, Ni）.
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.
