The poor contact and side reactions between Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)and lithium(Li)anode cause uneven Li plating and high interfacial impendence,which greatly hinder the practical application of LATP...The poor contact and side reactions between Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)and lithium(Li)anode cause uneven Li plating and high interfacial impendence,which greatly hinder the practical application of LATP in high-energy density solid-state Li metal batteries.In this work,a multifunctional ferroelectric BaTiO_(3)(BTO)/poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)(P[VDF-TrFE-CTFE])composite interlayer(B-TERB)is constructed between LATP and Li metal anode,which not only suppresses the Li dendrite growth,but also improves the interfacial stability and maintains the intimate interfacial contact to significantly decrease the interfacial resistance by two orders of magnitude.The B-TERB interlayer generates a uniform electric field to induce a uniform and lateral Li deposition,and therefore avoids the side reactions between Li metal and LATP achieving excellent interface stability.As a result,the Li/LATP@B-TERB/Li symmetrical batteries can stably cycle for 1800 h at 0.2 mA cm^(-2)and 1000 h at 0.5 mA cm^(-2).The solid-state LiFePO_(4)/LATP@B-TERB/Li full batteries also exhibit excellent cycle performance for 250 cycles at 0.5 C and room temperature.This work proposes a novel strategy to design multifunctional ferroelectric interlayer between ceramic electrolytes and Li metal to enable stable room-temperature cycling performance.展开更多
Security risks of flammability and explosion represent major problems with the use of conventional lithium rechargeable batteries using a liquid electrolyte.The application of solid-state electrolytes could effectivel...Security risks of flammability and explosion represent major problems with the use of conventional lithium rechargeable batteries using a liquid electrolyte.The application of solid-state electrolytes could effectively help to avoid these safety concerns.However,integrating the solid-state electrolytes into the all-solid-state lithium batteries is still a huge challenge mainly due to the high interfacial resistance present in the entire battery,especially at the interface between the cathode and the solid-state electrolyte pellet and the interfaces inside the cathode.Herein,recent progress made from investigations of cathode/solid-state electrolyte interfacial behaviors including the contact problem,the interlayer diffusion issue,the space-charge layer effect,and electrochemical compatibility is presented according to the classification of oxide-,sulfide-,and polymer-based solid-state electrolytes.We also propose strategies for the construction of ideal next-generation cathode/solid-state electrolyte interfaces with high room-temperature ionic conductivity,stable interfacial contact during long cycling,free formation of the space-charge region,and good compatibility with high-voltage cathodes.展开更多
To provide reference for fertilizer application of sugarcane planting in Xinping County,this paper analyzed nutrient content of topsoil according to the nutrient indicators established in the Second Soil Census. The r...To provide reference for fertilizer application of sugarcane planting in Xinping County,this paper analyzed nutrient content of topsoil according to the nutrient indicators established in the Second Soil Census. The results show that 51. 76% soil in sugarcane planting area of Xinping County is faintly acid,50. 88% soil has relatively low organic matter,45. 88% soil lacks alkali-hydrolyzable nitrogen( N),26. 47% soil lacks phosphorus( P),50. 29% soil lacks potassium( K),37. 14% soil lacks sulfur( S),12. 86% soil lacks magnesium( Mg),10% soil lacks manganese( Mn),and 31. 43% soil lacks zinc( Zn). In the sugarcane production,it is required to pay attention to increase of application of organic fertilizer,to foster soil fertility,supplement boron fertilizer,to keep balance of soil nutrients.展开更多
Ferrites are the most widely used microwave absorbing materials to deal with the threat of electromagnetic(EM)pollution.However,the lack of sufficient dielectric loss capacity is the main challenge that limits their a...Ferrites are the most widely used microwave absorbing materials to deal with the threat of electromagnetic(EM)pollution.However,the lack of sufficient dielectric loss capacity is the main challenge that limits their applications.To cope with this challenge,three high-entropy(HE)spineltype ferrite ceramics including(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4),(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))Fe_(2)O_(4),and(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Zn_(0.2))Fe_(2)O_(4)were designed and successfully prepared through solid state synthesis.The results show that all three HE MFe_(2)O_(4) samples exhibit synergetic dielectric loss and magnetic loss.The good magnetic loss ability is due to the presence of magnetic components;while the enhanced dielectric properties are attributed to nano-domain,hopping mechanism of resonance effect and HE effect.Among three HE spinels,(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4)shows the best EM wave absorption performance,e.g.,its minimum reflection loss(RL_(min))reaches-35.10 dB at 6.78 GHz with a thickness of 3.5 mm,and the optimized effective absorption bandwidth(EAB)is 7.48 GHz from 8.48 to 15.96 GHz at the thickness of 2.4 mm.Due to the easy preparation and strong EM dissipation ability,HE MFe_(2)O_(4) are promising as a new type of EM absorption materials.展开更多
Lithium sulfide(Li_(2)S)is a promising cathode for a practical lithium-sulfur battery as it can be coupled with various safe lithium-free anodes.However,the high activation potential(>3.5 V)together with the shuttl...Lithium sulfide(Li_(2)S)is a promising cathode for a practical lithium-sulfur battery as it can be coupled with various safe lithium-free anodes.However,the high activation potential(>3.5 V)together with the shuttling of lithium polysulfides(LiPSs)bottleneck its practical uses.We are trying to present a catalysis solution to solve both problems simultaneously,specially with twinborn heterostructure to shoot off the trouble in interfacial contact between two solids,catalyst and Li_(2)S.As a typical example,a Co9S8/Li_(2)S heterostructure is reported here as a novel self-catalytic cathode through a co-recrystallization followed by a one-step carbothermic conversion.Co9S8 as the catalyst effectively lowers the Li_(2)S activation potential(<2.4 V)due to fully integrated and contacted interfaces and consistently promotes the conversion of LiPSs to suppress the shuttling.The obtained freestanding cathode of Co9S8/Li_(2)S heterostructures encapsulated in three-dimensional graphene shows a high capacity,reaching 92.6%of Li_(2)S theoretical capacity,high rate performance(739 mAh g1 at 2 C),and a low capacity fading(0.039%per cycle at 1 C over 900 cycles).Even under a high Li_(2)S loading of 12 mg cm^(-2)and a low E/S ratio of 5μL mgLi_(2)S^(-1),86%of theoretical capacity can be utilized.展开更多
The replacement of liquid organic electrolytes with solid-state electrolytes(SSEs)is a feasible way to solve the safety issues and improve the energy density of lithium batteries.Developing SSEs materials that can wel...The replacement of liquid organic electrolytes with solid-state electrolytes(SSEs)is a feasible way to solve the safety issues and improve the energy density of lithium batteries.Developing SSEs materials that can well match with high-voltage cathodes and lithium metal anode is quite significant to develop high-energy-density lithium batteries.Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)SSE with NASICON structure exhibits high ionic conductivity,low cost and superior air stability,which enable it as one of the most hopeful candidates for all-solidstate batteries(ASSBs).However,the high interfacial impedance between LATP and electrodes,and the severe interfacial side reactions with the lithium metal greatly limit its applications in ASSBs.This review introduces the crystal structure and ion transport mechanisms of LATP and summarizes the key factors affecting the ionic conductivity.The side reaction mechanisms of LATP with Li metal and the promising strategies for optimizing interfacial compatibility are reviewed.We also summarize the applications of LATP including as surface coatings of cathode particles,ion transport network additives and inorganic fillers of composite polymer electrolytes.At last,this review proposes the challenges and the future development directions of LATP in SSBs.展开更多
The low initial Coulombic efficiency(ICE)is a significant problem hindering the practical uses of carbon anodes in sodium-ion batteries(SIBs),especially for the carbons with large surface area.Presodiation is an effec...The low initial Coulombic efficiency(ICE)is a significant problem hindering the practical uses of carbon anodes in sodium-ion batteries(SIBs),especially for the carbons with large surface area.Presodiation is an effective way to solve the above problem,but it always needs complicated operations and cannot suppress the unavoidable electrolyte decomposition in the assembled battery.Herein,we develop an ultrafast chemical presodiation method for reduced graphene oxide(rGO)using sodium naphthalene(Na-Nt)dissolved in dimethoxyethane(DME)solvent as a presodiation reagent.The presodiation effectively improves the ICE of rGO to 96.8%and forms an artificial solid electrolyte interphase(SEI)on its surface due to the decomposition of the formed complex between Na+and DME.The formed artificial SEI suppresses the excessive decomposition of electrolytes in the assembled battery,leading to a formation of uniform and inorganic component–rich SEI on rGO surface,which enables a rapid interfacial ion transfer.Therefore,the presodiated rGO showed excellent rate performance with a high capacity of 198.5 mAh g^(-1) at 5 A g^(-1).Moreover,excellent cycle stability indicated by the high capacity retention of 68.4%over 1000 cycles was also achieved,showing the poten-tial to promote the practical uses of high-rate rGO anode in SIBs.展开更多
严重的锂枝晶生长导致锂金属电池的循环稳定性差、安全隐患大,完全阻碍了其实际应用.本文提出了一种基于Li-Sn/Li_(3)N复合界面层的锂形核-扩散-生长机制,利用两组分的协同作用引导锂的水平沉积,从而抑制锂枝晶的垂直生长以及锂金属与...严重的锂枝晶生长导致锂金属电池的循环稳定性差、安全隐患大,完全阻碍了其实际应用.本文提出了一种基于Li-Sn/Li_(3)N复合界面层的锂形核-扩散-生长机制,利用两组分的协同作用引导锂的水平沉积,从而抑制锂枝晶的垂直生长以及锂金属与电解液之间的副反应.在锂沉积过程中,亲锂的Li-Sn合金优先捕获Li+在合金位点上形核,同时具有低扩散能垒和高锂离子电导率的Li_(3)N有效地将锂离子传输至形核位点,最终促进锂的横向生长.因此,即使在5 m A cm^(-2)的高电流密度和5 m A h cm^(-2)的大沉积容量下,组装的对称电池也可以稳定循环1600 h.与负载高达8.2 mg cm^(-2)的Li Fe PO_(4)正极组装的电池,在循环1000圈以后,容量保持率为93.4%,远高于未修饰锂片(64.8%).此外,Li-Sn/Li_(3)N修饰的锂负极与Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)正极组装的电池循环稳定性也明显优于未修饰锂片组装的电池.锂成核-扩散-生长机制为解决垂直生长的锂枝晶难题、实现高稳定锂金属电池开辟了一条有前景的途径.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
基金supported by National Natural Science Foundation of China(No.U2001220)Local Innovative Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01N111)+1 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center(XMHT20200203006)Shenzhen Technical Plan Project(Nos.RCJC20200714114436091,JCYJ20180508152210821,and JCYJ20180508152135822).
文摘The poor contact and side reactions between Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)and lithium(Li)anode cause uneven Li plating and high interfacial impendence,which greatly hinder the practical application of LATP in high-energy density solid-state Li metal batteries.In this work,a multifunctional ferroelectric BaTiO_(3)(BTO)/poly(vinylidene fluoride-co-trifluoroethylene-co-chlorotrifluoroethylene)(P[VDF-TrFE-CTFE])composite interlayer(B-TERB)is constructed between LATP and Li metal anode,which not only suppresses the Li dendrite growth,but also improves the interfacial stability and maintains the intimate interfacial contact to significantly decrease the interfacial resistance by two orders of magnitude.The B-TERB interlayer generates a uniform electric field to induce a uniform and lateral Li deposition,and therefore avoids the side reactions between Li metal and LATP achieving excellent interface stability.As a result,the Li/LATP@B-TERB/Li symmetrical batteries can stably cycle for 1800 h at 0.2 mA cm^(-2)and 1000 h at 0.5 mA cm^(-2).The solid-state LiFePO_(4)/LATP@B-TERB/Li full batteries also exhibit excellent cycle performance for 250 cycles at 0.5 C and room temperature.This work proposes a novel strategy to design multifunctional ferroelectric interlayer between ceramic electrolytes and Li metal to enable stable room-temperature cycling performance.
基金National Natural Science Foundation of China(U2001220)the Local Innovative Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01N111)+1 种基金the Shenzhen Technical Plan Project(Nos.JCYJ20180508152210821,JCYJ20170817161221958,and JCYJ20180508152135822)the Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center(XMHT20200203006).
文摘Security risks of flammability and explosion represent major problems with the use of conventional lithium rechargeable batteries using a liquid electrolyte.The application of solid-state electrolytes could effectively help to avoid these safety concerns.However,integrating the solid-state electrolytes into the all-solid-state lithium batteries is still a huge challenge mainly due to the high interfacial resistance present in the entire battery,especially at the interface between the cathode and the solid-state electrolyte pellet and the interfaces inside the cathode.Herein,recent progress made from investigations of cathode/solid-state electrolyte interfacial behaviors including the contact problem,the interlayer diffusion issue,the space-charge layer effect,and electrochemical compatibility is presented according to the classification of oxide-,sulfide-,and polymer-based solid-state electrolytes.We also propose strategies for the construction of ideal next-generation cathode/solid-state electrolyte interfaces with high room-temperature ionic conductivity,stable interfacial contact during long cycling,free formation of the space-charge region,and good compatibility with high-voltage cathodes.
基金Supported by Special Fund for Scientific Research of Public Welfare Industry(Agriculture)(201003014-5)
文摘To provide reference for fertilizer application of sugarcane planting in Xinping County,this paper analyzed nutrient content of topsoil according to the nutrient indicators established in the Second Soil Census. The results show that 51. 76% soil in sugarcane planting area of Xinping County is faintly acid,50. 88% soil has relatively low organic matter,45. 88% soil lacks alkali-hydrolyzable nitrogen( N),26. 47% soil lacks phosphorus( P),50. 29% soil lacks potassium( K),37. 14% soil lacks sulfur( S),12. 86% soil lacks magnesium( Mg),10% soil lacks manganese( Mn),and 31. 43% soil lacks zinc( Zn). In the sugarcane production,it is required to pay attention to increase of application of organic fertilizer,to foster soil fertility,supplement boron fertilizer,to keep balance of soil nutrients.
基金supported by the National Key Research and Development Program of China (2021YFF0500600)National Natural Science Foundation of China (No.U2001220)+1 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center (XMHT20200203006)Shenzhen Technical Plan Project (RCJC20200714114436091,JCYJ20220818101003007,and JCYJ20220818101003008)。
基金supported by the National Natural Science Foundation of China(Grant Nos.51802289 and 51972089)Financial supports of the Science Foundation for the Excellent Youth Scholars of Henan Province(Grant No.212300410089)the Support Program for Scientific and Technological Innovation Talents of Higher Education in Henan Province(Grant No.21HASTIT004)。
文摘Ferrites are the most widely used microwave absorbing materials to deal with the threat of electromagnetic(EM)pollution.However,the lack of sufficient dielectric loss capacity is the main challenge that limits their applications.To cope with this challenge,three high-entropy(HE)spineltype ferrite ceramics including(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4),(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Cu_(0.2))Fe_(2)O_(4),and(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Zn_(0.2))Fe_(2)O_(4)were designed and successfully prepared through solid state synthesis.The results show that all three HE MFe_(2)O_(4) samples exhibit synergetic dielectric loss and magnetic loss.The good magnetic loss ability is due to the presence of magnetic components;while the enhanced dielectric properties are attributed to nano-domain,hopping mechanism of resonance effect and HE effect.Among three HE spinels,(Mg_(0.2)Mn_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2))Fe_(2)O_(4)shows the best EM wave absorption performance,e.g.,its minimum reflection loss(RL_(min))reaches-35.10 dB at 6.78 GHz with a thickness of 3.5 mm,and the optimized effective absorption bandwidth(EAB)is 7.48 GHz from 8.48 to 15.96 GHz at the thickness of 2.4 mm.Due to the easy preparation and strong EM dissipation ability,HE MFe_(2)O_(4) are promising as a new type of EM absorption materials.
基金National Key Research and Development Program of China,Grant/Award Numbers:2018YFE0124500,2021YFF0500600National Natural Science Foundation of China,Grant/Award Numbers:52022041,51932005+1 种基金The Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program,Grant/Award Number:2017BT01N111Shenzhen Basic Research Project,Grant/Award Number:JCYJ20180508152037520。
文摘Lithium sulfide(Li_(2)S)is a promising cathode for a practical lithium-sulfur battery as it can be coupled with various safe lithium-free anodes.However,the high activation potential(>3.5 V)together with the shuttling of lithium polysulfides(LiPSs)bottleneck its practical uses.We are trying to present a catalysis solution to solve both problems simultaneously,specially with twinborn heterostructure to shoot off the trouble in interfacial contact between two solids,catalyst and Li_(2)S.As a typical example,a Co9S8/Li_(2)S heterostructure is reported here as a novel self-catalytic cathode through a co-recrystallization followed by a one-step carbothermic conversion.Co9S8 as the catalyst effectively lowers the Li_(2)S activation potential(<2.4 V)due to fully integrated and contacted interfaces and consistently promotes the conversion of LiPSs to suppress the shuttling.The obtained freestanding cathode of Co9S8/Li_(2)S heterostructures encapsulated in three-dimensional graphene shows a high capacity,reaching 92.6%of Li_(2)S theoretical capacity,high rate performance(739 mAh g1 at 2 C),and a low capacity fading(0.039%per cycle at 1 C over 900 cycles).Even under a high Li_(2)S loading of 12 mg cm^(-2)and a low E/S ratio of 5μL mgLi_(2)S^(-1),86%of theoretical capacity can be utilized.
基金Key-Area Research and Development Program of Guangdong Province,Grant/Award Number:2020B090919001National Natural Science Foundation of China,Grant/Award Number:U2001220+1 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center,Grant/Award Number:XMHT20200203006Shenzhen Technical Plan Project,Grant/Award Number:JCYJ20180508152210821,JCYJ20170817161221958,JCYJ20180508152135822。
文摘The replacement of liquid organic electrolytes with solid-state electrolytes(SSEs)is a feasible way to solve the safety issues and improve the energy density of lithium batteries.Developing SSEs materials that can well match with high-voltage cathodes and lithium metal anode is quite significant to develop high-energy-density lithium batteries.Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)SSE with NASICON structure exhibits high ionic conductivity,low cost and superior air stability,which enable it as one of the most hopeful candidates for all-solidstate batteries(ASSBs).However,the high interfacial impedance between LATP and electrodes,and the severe interfacial side reactions with the lithium metal greatly limit its applications in ASSBs.This review introduces the crystal structure and ion transport mechanisms of LATP and summarizes the key factors affecting the ionic conductivity.The side reaction mechanisms of LATP with Li metal and the promising strategies for optimizing interfacial compatibility are reviewed.We also summarize the applications of LATP including as surface coatings of cathode particles,ion transport network additives and inorganic fillers of composite polymer electrolytes.At last,this review proposes the challenges and the future development directions of LATP in SSBs.
基金Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program,Grant/Award Number:2017BT01N111Guangdong Special Support Program,Grant/Award Number:2017TQ04C664+3 种基金National Key Research and Development Program of China,Grant/Award Number:2018YFE0124500National Natural Science Foundation of China,Grant/Award Numbers:51972190,52022041Shenzhen Basic Research Project,Grant/Award Numbers:JCYJ20180508152019687,JCYJ20180508152037520Shenzhen Graphene Manufacturing Innovation Center,Grant/Award Number:201901161513。
文摘The low initial Coulombic efficiency(ICE)is a significant problem hindering the practical uses of carbon anodes in sodium-ion batteries(SIBs),especially for the carbons with large surface area.Presodiation is an effective way to solve the above problem,but it always needs complicated operations and cannot suppress the unavoidable electrolyte decomposition in the assembled battery.Herein,we develop an ultrafast chemical presodiation method for reduced graphene oxide(rGO)using sodium naphthalene(Na-Nt)dissolved in dimethoxyethane(DME)solvent as a presodiation reagent.The presodiation effectively improves the ICE of rGO to 96.8%and forms an artificial solid electrolyte interphase(SEI)on its surface due to the decomposition of the formed complex between Na+and DME.The formed artificial SEI suppresses the excessive decomposition of electrolytes in the assembled battery,leading to a formation of uniform and inorganic component–rich SEI on rGO surface,which enables a rapid interfacial ion transfer.Therefore,the presodiated rGO showed excellent rate performance with a high capacity of 198.5 mAh g^(-1) at 5 A g^(-1).Moreover,excellent cycle stability indicated by the high capacity retention of 68.4%over 1000 cycles was also achieved,showing the poten-tial to promote the practical uses of high-rate rGO anode in SIBs.
基金supported by the Key-Area Research and Development Program of Guangdong Province (2020B090919001)the National Natural Science Foundation of China (U2001220)+3 种基金Local Innovative Research Teams Project of Guangdong Pearl River Talents Program (2017BT01N111)Shenzhen Technical Plan Project (JCYJ20180508152210821, JCYJ20170817161221958, and JCYJ20180508152135822)the All-Solid-State Lithium Battery Electrolyte Engineering Research Center (XMHT202002030)Shenzhen Graphene Manufacturing Innovation Center (201901161513)
文摘严重的锂枝晶生长导致锂金属电池的循环稳定性差、安全隐患大,完全阻碍了其实际应用.本文提出了一种基于Li-Sn/Li_(3)N复合界面层的锂形核-扩散-生长机制,利用两组分的协同作用引导锂的水平沉积,从而抑制锂枝晶的垂直生长以及锂金属与电解液之间的副反应.在锂沉积过程中,亲锂的Li-Sn合金优先捕获Li+在合金位点上形核,同时具有低扩散能垒和高锂离子电导率的Li_(3)N有效地将锂离子传输至形核位点,最终促进锂的横向生长.因此,即使在5 m A cm^(-2)的高电流密度和5 m A h cm^(-2)的大沉积容量下,组装的对称电池也可以稳定循环1600 h.与负载高达8.2 mg cm^(-2)的Li Fe PO_(4)正极组装的电池,在循环1000圈以后,容量保持率为93.4%,远高于未修饰锂片(64.8%).此外,Li-Sn/Li_(3)N修饰的锂负极与Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)正极组装的电池循环稳定性也明显优于未修饰锂片组装的电池.锂成核-扩散-生长机制为解决垂直生长的锂枝晶难题、实现高稳定锂金属电池开辟了一条有前景的途径.
基金supported by the National Natural Science Foundation of China(U2001220)Key-Area Research and Development Program of Guangdong Province(2020B090919001)+2 种基金Shenzhen All-Solid-State Lithium Battery Electrolyte Engineering Research Center(XMHT20200203006)Shenzhen Technical Plan Project(RCJC20200714114436091,JCYJ20180508152210821JCYJ20180508152135822)。
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.