The preparation of LiNi_(0.8)Co_(0.2)O_2 was discussed by the multiply sintering method for solid reaction, in which the sintered material was smashed, ground and pelletted between two successive sintering steps. The...The preparation of LiNi_(0.8)Co_(0.2)O_2 was discussed by the multiply sintering method for solid reaction, in which the sintered material was smashed, ground and pelletted between two successive sintering steps. The optimum technological condition was obtained through orthogonal experiments by L_9(3~4) and DTA analysis. The result indicates that the factors of effecting the electrochemical properties of synthesized LiNi_(0.8)Co_(0.2)O_2 are molar ratio of Li/Ni/Co, oxygen pressure, homothermal time, the final sintering temperature in turn according to its importance. The oxygen pressure is reviewed independently and the technological condition is further optimized. With the same method, rare earth element Ce was studied as substitute element of Co and the cathode material of LiNi_(0.95)Ce_(0.05)O_2 with excellent electrochemical properties was prepared. The electrochemical testing results of LiNi_(0.8)Co_(0.2)O_2 and LiNi_(0.95)Ce_(0.05)O_2 experimental batteries show that discharge capacities of them reach 165 and 148 mAh·g^(-1) respectively and the persistence is more than 9 h at 3.7 V.展开更多
The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poo...The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poor crystal structure stability of Ni-rich cathode.Several coating strategies are previously employed to enhance the stability of the cathodic interface and crystal structure for Ni-rich cathode.However,these methods can hardly achieve simplicity and high efficiency simultaneously.In this work,polyacrylic acid(PAA)replaced traditional PVDF as a binder for cathode,which can achieve a uniform PAA-Li(LixPAA(0<x≤1))coating layer on the surface of single-crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)due to H^(+)/Li^(+)exchange reaction during the initial charging-discharging process.The formation of PAA-Li coating layer on cathode can promote interfacial Li^(+)transport and enhance the stability of the cathodic interface.Furthermore,the partially-protonated surface of SC-NCM83 casued by H^(+)/Li^(+)exchange reaction can restrict Ni ions transport to enhance the crystal structure stability.The proposed SC-NCM83-PAA exhibits superior cycling performance with a retention of 92%compared with that(57.3%)of SC-NCM83-polyvinylidene difluoride(PVDF)after 200 cycles.This work provides a practical strategy to construct high-performance cathodes for ASSBs.展开更多
氟是废旧锂电池回收难以回避的典型杂质元素,其迁移转化行为复杂,制约了高品质正极材料的可控再生制备.本研究通过揭示废旧锂电池在热解、浸出及高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料再生过程中氟的迁移转化规律,为氟的定向调控...氟是废旧锂电池回收难以回避的典型杂质元素,其迁移转化行为复杂,制约了高品质正极材料的可控再生制备.本研究通过揭示废旧锂电池在热解、浸出及高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料再生过程中氟的迁移转化规律,为氟的定向调控及材料的可控再生制备奠定理论基础实验结果表明:热解过程中部分氟(45.71%)以气态热解产物的形式释放到大气中,而另一部分氟(52.34%)则向废三元材料的晶格内发生迁移,并随着湿法浸出溶解到镍钴锰的浸出液中.浸出液中少量的氟会在共沉淀制备前驱体过程中迁移到Ni_(0.9)Co_(0.05)Mn_(0.05)(OH)2前驱体材料,并随着配锂烧结掺杂到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料表面.进一步通过调控氟含量发现,当浸出液中氟浓度控制在0.30 g L^(-1)时,引入到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料中的氟不仅不会引起不利相变,而且能够稳定材料结构,从而有效提升再生高镍材料的循环稳定性(1 C电流密度下循环100圈的容量保持率高达95.7%).因此,本研究不仅揭示了废旧锂电池回收过程中氟的迁移转化行为,而且可控再生制备了高性能氟掺杂高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)正极材料,为废旧锂离子电池回收过程中氟的调控提供了理论依据.展开更多
LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)secondary particles with high tap density have a great potential for high volumetric energy density lithium(Li)-ion power bat-tery.However,the ionic conductivity mechanism of NCA ...LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)secondary particles with high tap density have a great potential for high volumetric energy density lithium(Li)-ion power bat-tery.However,the ionic conductivity mechanism of NCA with compact structure is still a suspense,especially the function of grain boundaries.Herein,we sys-tematically investigate the Li-ion transport behavior in both the primitive NCA(PNCA)secondary sphere densely grown by single-crystal primary grains and ball-milled NCA(MNCA)nanosized particle to reveal the role of grain bound-aries for Li-ion transport.The PNCA and MNCA have comparable Li-ion dif-fusion coefficients and rate performance.Moreover,the graphene nanosheet conductive additive only mildly affects the Li-ion diffusion in PNCA cathode,while which severely blocks the Li-ion transport in MNCA cathode.Through high-resolution transmission electron microscopy and electron energy loss spec-troscopy,we clearly observe Li-ion depletion at lower state of charge(SOC)and Li-ion aggregation at high SOC along the grain boundaries of PNCA secondary particles during high-rate lithiation process.The grain boundaries can construct an interconnected Li-ion transport network for highly efficient Li-ion transport,which contributes to excellent high-rate performance of compact PNCA sec-ondary particles.These findings present new strategy and deep insight in design-ing compact materials with excellent high-rate performance.展开更多
LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA) is a promising cathode for sulfide-based solid-state lithium batteries(ASSLBs)profiting from its high specific capacity and voltage plateau, which yielding high energy density. H...LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA) is a promising cathode for sulfide-based solid-state lithium batteries(ASSLBs)profiting from its high specific capacity and voltage plateau, which yielding high energy density. However, the inferior interfacial stability between the bare NCA and sulfides limits its electrochemical performance. Hereien, the dual-electrolyte layer is proposed to mitigate this effect and enhance the battery performances of NCA-based ASSLIBs. The Li_(3)InCl_6 wih high conductivity and excellent electrochemcial stability act both as an ion additives to promote Li-ion diffusion across the interface in the cathode and as a buffer layer between the cathode layer and the solid electrolyte layer to avoid side reactions and improve the interface stability. The corresponding battery exhibits high discharge capacities and superior cyclabilities at both room and elevated temperatures. It exhibits discharge performance of 237.04 and216.07 m Ah/g at 0.1 and 0.5 C, respectively, when cycled at 60 ℃, and sustains 95.9% of the capacity after100 cycles at 0.5 C. The work demonstrates a simple strategy to ensure the superior performances of NCA in sulfide-based ASSLBs.展开更多
文摘The preparation of LiNi_(0.8)Co_(0.2)O_2 was discussed by the multiply sintering method for solid reaction, in which the sintered material was smashed, ground and pelletted between two successive sintering steps. The optimum technological condition was obtained through orthogonal experiments by L_9(3~4) and DTA analysis. The result indicates that the factors of effecting the electrochemical properties of synthesized LiNi_(0.8)Co_(0.2)O_2 are molar ratio of Li/Ni/Co, oxygen pressure, homothermal time, the final sintering temperature in turn according to its importance. The oxygen pressure is reviewed independently and the technological condition is further optimized. With the same method, rare earth element Ce was studied as substitute element of Co and the cathode material of LiNi_(0.95)Ce_(0.05)O_2 with excellent electrochemical properties was prepared. The electrochemical testing results of LiNi_(0.8)Co_(0.2)O_2 and LiNi_(0.95)Ce_(0.05)O_2 experimental batteries show that discharge capacities of them reach 165 and 148 mAh·g^(-1) respectively and the persistence is more than 9 h at 3.7 V.
基金the financial support from the National Natural Science Foundation of China(Nos.52034011 and 52204328)the Science and Technology Innovation Program of Hunan Province(2023RC305)the Changsha Municipal Natural Science Foundation(kq2202085)。
文摘The poor electrochemical performance of all-solid-state batteries(ASSBs),which is assemblied by Ni-rich cathode and poly(ethylene oxide)(PEO)-based electrolytes,can be attributed to unstable cathodic interface and poor crystal structure stability of Ni-rich cathode.Several coating strategies are previously employed to enhance the stability of the cathodic interface and crystal structure for Ni-rich cathode.However,these methods can hardly achieve simplicity and high efficiency simultaneously.In this work,polyacrylic acid(PAA)replaced traditional PVDF as a binder for cathode,which can achieve a uniform PAA-Li(LixPAA(0<x≤1))coating layer on the surface of single-crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)due to H^(+)/Li^(+)exchange reaction during the initial charging-discharging process.The formation of PAA-Li coating layer on cathode can promote interfacial Li^(+)transport and enhance the stability of the cathodic interface.Furthermore,the partially-protonated surface of SC-NCM83 casued by H^(+)/Li^(+)exchange reaction can restrict Ni ions transport to enhance the crystal structure stability.The proposed SC-NCM83-PAA exhibits superior cycling performance with a retention of 92%compared with that(57.3%)of SC-NCM83-polyvinylidene difluoride(PVDF)after 200 cycles.This work provides a practical strategy to construct high-performance cathodes for ASSBs.
基金supported by the National Natural Science Foundation of China (51904340)the Natural Science Foundation of Hunan (2021JJ2020066)+1 种基金the National Key Research and Development Program (2019YFC1907801, 2019YFC1907803 and 2019YFC1907804)the Central South University Innovation-Driven Research Programme (2023CXQD009)。
文摘氟是废旧锂电池回收难以回避的典型杂质元素,其迁移转化行为复杂,制约了高品质正极材料的可控再生制备.本研究通过揭示废旧锂电池在热解、浸出及高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料再生过程中氟的迁移转化规律,为氟的定向调控及材料的可控再生制备奠定理论基础实验结果表明:热解过程中部分氟(45.71%)以气态热解产物的形式释放到大气中,而另一部分氟(52.34%)则向废三元材料的晶格内发生迁移,并随着湿法浸出溶解到镍钴锰的浸出液中.浸出液中少量的氟会在共沉淀制备前驱体过程中迁移到Ni_(0.9)Co_(0.05)Mn_(0.05)(OH)2前驱体材料,并随着配锂烧结掺杂到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料表面.进一步通过调控氟含量发现,当浸出液中氟浓度控制在0.30 g L^(-1)时,引入到再生LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)材料中的氟不仅不会引起不利相变,而且能够稳定材料结构,从而有效提升再生高镍材料的循环稳定性(1 C电流密度下循环100圈的容量保持率高达95.7%).因此,本研究不仅揭示了废旧锂电池回收过程中氟的迁移转化行为,而且可控再生制备了高性能氟掺杂高镍LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)正极材料,为废旧锂离子电池回收过程中氟的调控提供了理论依据.
基金National Natural Science Founda-tion of China,Grant/Award Number:U2001220Local Innovative Research Teams Project of Guangdong Pearl River Talents Program,Grant/Award Number:2017BT01N111+2 种基金Shenzhen Technical Plan Project,Grant/Award Numbers:JCYJ20180508152135822,JCYJ20180508152210821,JCYJ20170412170706047Shenzhen graphene manufacturing innova-tion center,Grant/Award Number:201901161513Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center,Grant/Award Number:XMHT20200203006。
文摘LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)secondary particles with high tap density have a great potential for high volumetric energy density lithium(Li)-ion power bat-tery.However,the ionic conductivity mechanism of NCA with compact structure is still a suspense,especially the function of grain boundaries.Herein,we sys-tematically investigate the Li-ion transport behavior in both the primitive NCA(PNCA)secondary sphere densely grown by single-crystal primary grains and ball-milled NCA(MNCA)nanosized particle to reveal the role of grain bound-aries for Li-ion transport.The PNCA and MNCA have comparable Li-ion dif-fusion coefficients and rate performance.Moreover,the graphene nanosheet conductive additive only mildly affects the Li-ion diffusion in PNCA cathode,while which severely blocks the Li-ion transport in MNCA cathode.Through high-resolution transmission electron microscopy and electron energy loss spec-troscopy,we clearly observe Li-ion depletion at lower state of charge(SOC)and Li-ion aggregation at high SOC along the grain boundaries of PNCA secondary particles during high-rate lithiation process.The grain boundaries can construct an interconnected Li-ion transport network for highly efficient Li-ion transport,which contributes to excellent high-rate performance of compact PNCA sec-ondary particles.These findings present new strategy and deep insight in design-ing compact materials with excellent high-rate performance.
基金supported by the National Key Research and Development Program (No.2021YFB2500200)the National Natural Science Foundation of China (No.52177214)supported by China Fujian Energy Devices Science and Technology Innovation Laboratory Open Fund (No.21C-OP202211)。
文摘LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA) is a promising cathode for sulfide-based solid-state lithium batteries(ASSLBs)profiting from its high specific capacity and voltage plateau, which yielding high energy density. However, the inferior interfacial stability between the bare NCA and sulfides limits its electrochemical performance. Hereien, the dual-electrolyte layer is proposed to mitigate this effect and enhance the battery performances of NCA-based ASSLIBs. The Li_(3)InCl_6 wih high conductivity and excellent electrochemcial stability act both as an ion additives to promote Li-ion diffusion across the interface in the cathode and as a buffer layer between the cathode layer and the solid electrolyte layer to avoid side reactions and improve the interface stability. The corresponding battery exhibits high discharge capacities and superior cyclabilities at both room and elevated temperatures. It exhibits discharge performance of 237.04 and216.07 m Ah/g at 0.1 and 0.5 C, respectively, when cycled at 60 ℃, and sustains 95.9% of the capacity after100 cycles at 0.5 C. The work demonstrates a simple strategy to ensure the superior performances of NCA in sulfide-based ASSLBs.
