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
The performance degradation mechanism of ceramic fuel cell with NCAL(Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2))as symmetrical electrode and GDC as electrolyte in H2 is investigated.It is found that under the condition of 550◦...The performance degradation mechanism of ceramic fuel cell with NCAL(Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2))as symmetrical electrode and GDC as electrolyte in H2 is investigated.It is found that under the condition of 550◦C and constant current density of 0.2 A⋅cm^(-2),the output voltage of the cell is about 1.005 V in the initial 10 h and remains relatively stable.After 10 h,the voltage of the cell began to decrease gradually,and by 50 h,the voltage had decreased to 0.522 V.The results testing electrochemical performance of the cell and characterizing the cell materials before and after test using SEM,TOF-SIMS and FTIR indicate that the distribution of Li_(2)O/LiOH/Li_(2)CO_(3)compounds generated from NCAL anode in the cell plays a vital role in significantly improving the ionic conductivity of electrolyte and gas tightness of the cell.The dynamic migration of molten salt destroyed the continuity of molten salt in the cell,which in turn adversely impacted the ionic conductivity of electrolyte,gas tightness of the cell,and electrochemical reactions on both sides of the cathode and anode.These finally lead to the degradation of the cell performance.展开更多
Previous studies have found that the ceramic fuel cell using Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2)(NCAL)symmetrical electrode has obtained very good power generation performance in the temperature range of 450 to 550℃.Pr...Previous studies have found that the ceramic fuel cell using Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2)(NCAL)symmetrical electrode has obtained very good power generation performance in the temperature range of 450 to 550℃.Previous studies have pointed out that after being reduced by H2,NCAL anode will produce LiOH/Li2CO3 mixture and diffuse into the electrolyte,which results in the high ionic conductivity of the cell.In this study,the chemical reactivity of different oxide electrolytes such as CeO_(2),TiO_(2),ZrO_(2)and YSZ with LiOH and/or Li2CO3 and their effects on the electrochemical performance of the cell were studied.It is found that at 550◦C,only the open circuit voltage(OCV)of the cell using CeO_(2)as electrolyte can remain stable,and the maximum power density(MPD)of the CeO_(2)electrolyte cell reaches 599.6 mW⋅cm^(−2).The OCV of the cells with TiO_(2),ZrO_(2)and YSZ as electrolyte increased to the highest value within a few minutes,and the MPD of the cells was only more than 12 mW⋅cm^(−2).XRD,FT-IR,SEM-EDS and ICP-OES results indicate that the LiOH/Li2CO3 mixture diffuses into TiO_(2),ZrO_(2)and YSZ electrolytes and reacts with three oxides to produce Li2TiO3 and Li2ZrO3,respectively,which results in the low performance of the cell.展开更多
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.
基金supported by the National Natural Science Foundation of China(No.21978044).
文摘The performance degradation mechanism of ceramic fuel cell with NCAL(Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2))as symmetrical electrode and GDC as electrolyte in H2 is investigated.It is found that under the condition of 550◦C and constant current density of 0.2 A⋅cm^(-2),the output voltage of the cell is about 1.005 V in the initial 10 h and remains relatively stable.After 10 h,the voltage of the cell began to decrease gradually,and by 50 h,the voltage had decreased to 0.522 V.The results testing electrochemical performance of the cell and characterizing the cell materials before and after test using SEM,TOF-SIMS and FTIR indicate that the distribution of Li_(2)O/LiOH/Li_(2)CO_(3)compounds generated from NCAL anode in the cell plays a vital role in significantly improving the ionic conductivity of electrolyte and gas tightness of the cell.The dynamic migration of molten salt destroyed the continuity of molten salt in the cell,which in turn adversely impacted the ionic conductivity of electrolyte,gas tightness of the cell,and electrochemical reactions on both sides of the cathode and anode.These finally lead to the degradation of the cell performance.
基金the National Natural Science Foundation of China(No.21978044,No.51834004)。
文摘Previous studies have found that the ceramic fuel cell using Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2)(NCAL)symmetrical electrode has obtained very good power generation performance in the temperature range of 450 to 550℃.Previous studies have pointed out that after being reduced by H2,NCAL anode will produce LiOH/Li2CO3 mixture and diffuse into the electrolyte,which results in the high ionic conductivity of the cell.In this study,the chemical reactivity of different oxide electrolytes such as CeO_(2),TiO_(2),ZrO_(2)and YSZ with LiOH and/or Li2CO3 and their effects on the electrochemical performance of the cell were studied.It is found that at 550◦C,only the open circuit voltage(OCV)of the cell using CeO_(2)as electrolyte can remain stable,and the maximum power density(MPD)of the CeO_(2)electrolyte cell reaches 599.6 mW⋅cm^(−2).The OCV of the cells with TiO_(2),ZrO_(2)and YSZ as electrolyte increased to the highest value within a few minutes,and the MPD of the cells was only more than 12 mW⋅cm^(−2).XRD,FT-IR,SEM-EDS and ICP-OES results indicate that the LiOH/Li2CO3 mixture diffuses into TiO_(2),ZrO_(2)and YSZ electrolytes and reacts with three oxides to produce Li2TiO3 and Li2ZrO3,respectively,which results in the low performance of the cell.
