Layered Ni-rich oxide cathodes in lithium-ion batteries(LIBs)often struggle with poor thermal safety and capacity fade.Xin and colleagues’studies in Nature and Nature Energy demonstrate a novel high-entropy(compositi...Layered Ni-rich oxide cathodes in lithium-ion batteries(LIBs)often struggle with poor thermal safety and capacity fade.Xin and colleagues’studies in Nature and Nature Energy demonstrate a novel high-entropy(compositionally complex)doping strategy,introducing“cocktail effects”from multiple constituents.This approach substantially improves cycling performance and stability,reduces material cost,and may pave the way toward the development of advanced electrodes for next-generation LIBs.展开更多
Lithium argyrodite superionic conductors with the general formula Li_(6)PS_(5)X(X=Cl,Br,I)have been intensively investigated in recent years and successfully adopted in the field of solid-state batteries(SSBs).The tra...Lithium argyrodite superionic conductors with the general formula Li_(6)PS_(5)X(X=Cl,Br,I)have been intensively investigated in recent years and successfully adopted in the field of solid-state batteries(SSBs).The transport properties of argyrodite solid electrolytes(SEs)usually strongly depend on the degree of occupational disorder.Increasing disorder through complex doping or substitution has been shown to directly affect ionic conductivity.Herein,we explore a high-entropy lithium argyrodite of nominal composition Li_(6.6)[P_(0.2)Si_(0.2) Sn_(0.2)Ge_(0.2)Sb_(0.2)]S_(5)I.This material can be readily prepared by mechanochemistry.Using complementary diffraction techniques,nuclear magnetic resonance spectroscopy,and charge-transport measurements,we show that upon tailoring crystallinity and defect concentration by post-annealing at temperatures up to 220℃,a high room-temperature ionic conductivity of about 0.9 mS cm^(−1)(∼4.4 mS cm^(−1 )bulk conductivity)can be achieved.Both the as-prepared and annealed(at 220℃)samples were tested in pellet-stack SSB cells.The mechanochemically prepared glass-ceramic SE was found to exhibit superior performance,even outperforming commercially available Li_(6)PS_(5)Cl.Collectively,the results highlight the importance of considering structural aspects across different length scales when optimizing the properties of lithium argyrodites for SSB applications.展开更多
Layered transition metal oxides(LTMOs),such as the LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)family,are the primary class of cathode active materials(CAMs)commercialized and studied for conventional lithium-ion(LIB)and solid-state...Layered transition metal oxides(LTMOs),such as the LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)family,are the primary class of cathode active materials(CAMs)commercialized and studied for conventional lithium-ion(LIB)and solid-state battery(SSB)application.Despite nearly three decades of progress in improving stability,capacity,and cost,research has intensified to match global demand for high-performance materials.Nevertheless,(de)lithiation leads to irreversible degradation and subsequent capacity fading due to(chemo)mechanical particle disintegration and(electro)chemical side reactions.In this regard,surface and bulk modifications of CAMs by coating and doping/substitution are common strategies to enhance and support the electrochemical performance.Niobium has been featured in many studies exhibiting its advantages as a bulk dopant,where its ionic radius and unique valence character with respect to the metals used in LTMOs help prevent different degradation phenomena and therefore enhance performance.In addition,several niobium-based oxides(LiNbO_(3),Li_(3)NbO_(4),Nb_(2)O^(5),etc.)have been employed as a coating to increase cycling stability and rate capability through reduced surface degradation.Herein we illustrate how niobium serves as a coating constituent and a dopant,and discuss current understanding of underlying mechanisms,gaps in knowledge,and considerations for its use in a coating and/or as dopant in LTMO cathodes.展开更多
In recent years,investigations into improving the performance of bulk-type solid-state batteries(SSBs)have attracted much attention.This is due,in part,to the fact that they offer an opportunity to outperform the pres...In recent years,investigations into improving the performance of bulk-type solid-state batteries(SSBs)have attracted much attention.This is due,in part,to the fact that they offer an opportunity to outperform the present Li-ion battery technology in terms of energy density.Ni-rich Li_(1+x)(Ni_(1−y−z)Co_(y)Mn_(z))_(1−x)O_(2)(NCM)and lithium-thiophosphate-based solid electrolytes appear to be a promising material combination for application at the cathode side.Here,we report about exploratory investigations into the 1.5Li_(2)S/0.5P_(2)S_(5)/LiI phase system and demonstrate that a glassy solid electrolyte has more than an order of magnitude higher room-temperature ionic conductivity than the crystalline counterpart,tetragonal Li_(4)PS_(4)I with the P4/nmm space group(∼1.3 versus∼0.2 mS cm^(−1)).In addition,preliminary results show that usage of the glassy 1.5Li_(2)S–0.5P_(2)S_(5)–LiI in pellet stack SSB cells with an NCM622(60%Ni content)cathode and a Li_(4)Ti_(5)O_(12)anode leads to enhanced capacity retention when compared to the frequently employed argyr odite Li_(6)PS_(5)Cl solid electrolyte.This indicates that,apart from interfacial instabilities,the stiffness(modulus)of the solid electrolyte and associated mechanical effects may also impact significantly the long-term performance.Moreover,SSB cells with the glassy 1.5Li_(2)S–0.5P_(2)S5–LiI and high-loading cathode(∼22 mgNCM622 cm_(−2))manufactured using a slurry-casting process are found to cycle stably for 200 cycles at C/5 rate and 45℃,with areal capacities in excess of 3 mA h cm^(−2).展开更多
The research and development of advanced nanocoatings for high-capacity cathode materials is currently a hot topic in the field of solid-state batteries(SSBs).Protective surface coatings prevent direct contact between...The research and development of advanced nanocoatings for high-capacity cathode materials is currently a hot topic in the field of solid-state batteries(SSBs).Protective surface coatings prevent direct contact between the cathode material and solid electrolyte,thereby inhibiting detrimental interfacial decomposition reactions.This is particularly important when using lithium thiophosphate superionic solid electrolytes,as these materials exhibit a narrow electrochemical stability window,and therefore,are prone to degradation during battery operation.Herein we show that the cycling performance of LiNbO_(3)-coated Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2)cathode materials is strongly dependent on the sample history and(coating)synthesis conditions.We demonstrate that post-treatment in a pure oxygen atmosphere at 350℃results in the formation of a surface layer with a unique microstructure,consisting of LiNbO_(3)nanoparticles distributed in a carbonate matrix.If tested at 45℃and C/5 rate in pellet-stack SSB full cells with Li_(4)Ti_(5)O_(12)and Li_(6)PS_(5)Cl as anode material and solid electrolyte,respectively,around 80%of the initial specific discharge capacity is retained after 200 cycles(~160 mAh·g^(−1),~1.7 mAh·cm^(−2)).Our results highlight the importance of tailoring the coating chemistry to the electrode material(s)for practical SSB applications.展开更多
P2-type layered oxides with the general Na-deficient composition Na_(x)TMO_(2)(x<1,TM:transition metal)are a promising class of cathode materials for sodium-ion batteries.The open Na+transport pathways present in t...P2-type layered oxides with the general Na-deficient composition Na_(x)TMO_(2)(x<1,TM:transition metal)are a promising class of cathode materials for sodium-ion batteries.The open Na+transport pathways present in the structure lead to low diffusion barriers and enable high charge/discharge rates.However,a phase transition from P2 to O2 structure occurring above 4.2 V and metal dissolution at low potentials upon discharge results in rapid capacity degradation.In this work,we demonstrate the positive effect of configurational entropy on the stability of the crystal structure during battery operation.Three different compositions of layered P2-type oxides were synthesized by solid-state chemistry,Na_(0.67)(Mn_(0.55)Ni_(0.21)Co_(0.24))O_(2),Na_(0.67)(Mn_(0.45)Ni_(0.18)Co_(0.24)Ti_(0.1)Mg_(0.03))O_(2) and Na_(0.67)(Mn_(0.45)Ni_(0.18)Co_(0.18)Ti_(0.1)Mg_(0.03)Al_(0.04)Fe_(0.02))O_(2) with low,medium and high configurational entropy,respectively.The high-entropy cathode material shows lower structural transformation and Mn dissolution upon cycling in a wide voltage range from 1.5 to 4.6 V.Advanced operando techniques and post-mortem analysis were used to probe the underlying reaction mechanism thoroughly.Overall,the high-entropy strategy is a promising route for improving the electrochemical performance of P2 layered oxide cathodes for advanced sodium-ion battery applications.展开更多
This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed ...This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed on the carbonate species.Challenges and future research opportunities in the development of carbonate-containing protective nanocoatings for inorganic solid-state battery applications are also discussed.展开更多
Solid-state batteries(SSBs)are a promising next step in electrochemical energy storage but are plagued by a number of problems.In this study,we demonstrate the recurring issue of mechanical degradation because of volu...Solid-state batteries(SSBs)are a promising next step in electrochemical energy storage but are plagued by a number of problems.In this study,we demonstrate the recurring issue of mechanical degradation because of volume changes in layered Ni-rich oxide cathode materials in thiophosphate-based SSBs.Specifically,we explore superionic solid electrolytes(SEs)of different crystallinity,namely glassy 1.5Li_(2)S-0.5P_(2)S_(5)-LiI and argyrodite Li_(6)PS_(5)Cl,with emphasis on how they affect the cyclability of slurry-cast cathodes with NCM622(60%Ni)or NCM851005(85%Ni).The application of a combination of ex situ and in situ analytical techniques helped to reveal the benefits of using a SE with a low Young’s modulus.Through a synergistic interplay of(electro)chemical and(chemo)mechanical effects,the glassy SE employed in this work was able to achieve robust and stable interfaces,enabling intimate contact with the cathode material while at the same time mitigating volume changes.Our results emphasize the importance of considering chemical,electrochemical,and mechanical properties to realize long-term cycling performance in high-loading SSBs.展开更多
O3-type layered oxide cathodes,such as NaNi_(0.5)Mn_(0.5)O_(2),have garnered significant attention due to their high theoretical specific capacity while using abundant and low-cost sodium as intercalation species.Unli...O3-type layered oxide cathodes,such as NaNi_(0.5)Mn_(0.5)O_(2),have garnered significant attention due to their high theoretical specific capacity while using abundant and low-cost sodium as intercalation species.Unlike the lithium analog(LiNiO_(2)),NaNiO_(2)(NNO)exhibits poor electrochemical performance resulting from structural instability and inferior Coulomb efficiency.To enhance its cyclability for practical application,NNO was modified by titanium substitution to yield the O3-type NaNi_(0.9)Ti_(0.1)O_(2)(NNTO),which was successfully synthesized for the first time via a solid-state reaction.The mechanism behind its superior performance in comparison to that of similar materials is examined in detail using a variety of characterization techniques.NNTO delivers a specific discharge capacity of∼190 mAh g^(−1)and exhibits good reversibility,even in the presence of multiple phase transitions during cycling in a potential window of 2.0−4.2 V vs.Na^(+)/Na.This behavior can be attributed to the substituent,which helps maintain a larger interslab distance in the Na-deficient phases and to mitigate Jahn–Teller activity by reducing the average oxidation state of nickel.However,volume collapse at high potentials and irreversible lattice oxygen loss are still detrimental to the NNTO.Nevertheless,the performance can be further enhanced through coating and doping strategies.This not only positions NNTO as a promising next-generation cathode material,but also serves as inspiration for future research directions in the field of high-energy-density Na-ion batteries.展开更多
基金supported by the project on Natural Science Foundation of China(Key Project of 52131306)Carbon Emission Peak and Neutrality of Jiangsu Province(no.BE2022031-4)+1 种基金by research start-up funds from Southeast University(RF1028624081)Nanjing Normal University(184080H201B41).
文摘Layered Ni-rich oxide cathodes in lithium-ion batteries(LIBs)often struggle with poor thermal safety and capacity fade.Xin and colleagues’studies in Nature and Nature Energy demonstrate a novel high-entropy(compositionally complex)doping strategy,introducing“cocktail effects”from multiple constituents.This approach substantially improves cycling performance and stability,reduces material cost,and may pave the way toward the development of advanced electrodes for next-generation LIBs.
基金the Federal Ministry of Education and Research(BMBF)for funding within the project MELLi(03XP0447)supported by BASF SE.A portion of this research used resources at the Spallation Neutron Source,a DOE Office of Science User Facility operated by the Oak Ridge National LaboratoryThe beamtime was allocated to POWGEN on proposal number IPTS-29027。
文摘Lithium argyrodite superionic conductors with the general formula Li_(6)PS_(5)X(X=Cl,Br,I)have been intensively investigated in recent years and successfully adopted in the field of solid-state batteries(SSBs).The transport properties of argyrodite solid electrolytes(SEs)usually strongly depend on the degree of occupational disorder.Increasing disorder through complex doping or substitution has been shown to directly affect ionic conductivity.Herein,we explore a high-entropy lithium argyrodite of nominal composition Li_(6.6)[P_(0.2)Si_(0.2) Sn_(0.2)Ge_(0.2)Sb_(0.2)]S_(5)I.This material can be readily prepared by mechanochemistry.Using complementary diffraction techniques,nuclear magnetic resonance spectroscopy,and charge-transport measurements,we show that upon tailoring crystallinity and defect concentration by post-annealing at temperatures up to 220℃,a high room-temperature ionic conductivity of about 0.9 mS cm^(−1)(∼4.4 mS cm^(−1 )bulk conductivity)can be achieved.Both the as-prepared and annealed(at 220℃)samples were tested in pellet-stack SSB cells.The mechanochemically prepared glass-ceramic SE was found to exhibit superior performance,even outperforming commercially available Li_(6)PS_(5)Cl.Collectively,the results highlight the importance of considering structural aspects across different length scales when optimizing the properties of lithium argyrodites for SSB applications.
基金supported by BASF SE.The authors are grateful to the Federal Ministry of Education and Research(Bundesministerium für Bildung und Forschung,BMBF)for funding within the projects SUSTRAB(03XP0415D),UNIKAM(03XP0484B),and MELLi(03XP0447).
文摘Layered transition metal oxides(LTMOs),such as the LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)family,are the primary class of cathode active materials(CAMs)commercialized and studied for conventional lithium-ion(LIB)and solid-state battery(SSB)application.Despite nearly three decades of progress in improving stability,capacity,and cost,research has intensified to match global demand for high-performance materials.Nevertheless,(de)lithiation leads to irreversible degradation and subsequent capacity fading due to(chemo)mechanical particle disintegration and(electro)chemical side reactions.In this regard,surface and bulk modifications of CAMs by coating and doping/substitution are common strategies to enhance and support the electrochemical performance.Niobium has been featured in many studies exhibiting its advantages as a bulk dopant,where its ionic radius and unique valence character with respect to the metals used in LTMOs help prevent different degradation phenomena and therefore enhance performance.In addition,several niobium-based oxides(LiNbO_(3),Li_(3)NbO_(4),Nb_(2)O^(5),etc.)have been employed as a coating to increase cycling stability and rate capability through reduced surface degradation.Herein we illustrate how niobium serves as a coating constituent and a dopant,and discuss current understanding of underlying mechanisms,gaps in knowledge,and considerations for its use in a coating and/or as dopant in LTMO cathodes.
文摘In recent years,investigations into improving the performance of bulk-type solid-state batteries(SSBs)have attracted much attention.This is due,in part,to the fact that they offer an opportunity to outperform the present Li-ion battery technology in terms of energy density.Ni-rich Li_(1+x)(Ni_(1−y−z)Co_(y)Mn_(z))_(1−x)O_(2)(NCM)and lithium-thiophosphate-based solid electrolytes appear to be a promising material combination for application at the cathode side.Here,we report about exploratory investigations into the 1.5Li_(2)S/0.5P_(2)S_(5)/LiI phase system and demonstrate that a glassy solid electrolyte has more than an order of magnitude higher room-temperature ionic conductivity than the crystalline counterpart,tetragonal Li_(4)PS_(4)I with the P4/nmm space group(∼1.3 versus∼0.2 mS cm^(−1)).In addition,preliminary results show that usage of the glassy 1.5Li_(2)S–0.5P_(2)S_(5)–LiI in pellet stack SSB cells with an NCM622(60%Ni content)cathode and a Li_(4)Ti_(5)O_(12)anode leads to enhanced capacity retention when compared to the frequently employed argyr odite Li_(6)PS_(5)Cl solid electrolyte.This indicates that,apart from interfacial instabilities,the stiffness(modulus)of the solid electrolyte and associated mechanical effects may also impact significantly the long-term performance.Moreover,SSB cells with the glassy 1.5Li_(2)S–0.5P_(2)S5–LiI and high-loading cathode(∼22 mgNCM622 cm_(−2))manufactured using a slurry-casting process are found to cycle stably for 200 cycles at C/5 rate and 45℃,with areal capacities in excess of 3 mA h cm^(−2).
文摘The research and development of advanced nanocoatings for high-capacity cathode materials is currently a hot topic in the field of solid-state batteries(SSBs).Protective surface coatings prevent direct contact between the cathode material and solid electrolyte,thereby inhibiting detrimental interfacial decomposition reactions.This is particularly important when using lithium thiophosphate superionic solid electrolytes,as these materials exhibit a narrow electrochemical stability window,and therefore,are prone to degradation during battery operation.Herein we show that the cycling performance of LiNbO_(3)-coated Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2)cathode materials is strongly dependent on the sample history and(coating)synthesis conditions.We demonstrate that post-treatment in a pure oxygen atmosphere at 350℃results in the formation of a surface layer with a unique microstructure,consisting of LiNbO_(3)nanoparticles distributed in a carbonate matrix.If tested at 45℃and C/5 rate in pellet-stack SSB full cells with Li_(4)Ti_(5)O_(12)and Li_(6)PS_(5)Cl as anode material and solid electrolyte,respectively,around 80%of the initial specific discharge capacity is retained after 200 cycles(~160 mAh·g^(−1),~1.7 mAh·cm^(−2)).Our results highlight the importance of tailoring the coating chemistry to the electrode material(s)for practical SSB applications.
基金financial support from the China Scholarship Council(CSC)financial support by Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy,EXC 2154,project number 390874152+8 种基金financial support from the Federal Ministry of Education and Research(Bundesministerium für Bildung und Forschung,BMBF)under the project‘KaSiLi’(03XP0254D)in the competence cluster‘Excell-BattMat’financial support from the Helmholtz Association(DigiBat project)support by the German Research Foundation(to H H,Grant No.HA 1344/43-1)is gratefully acknowledgedsupport from EnABLES and EPISTORE,projects funded by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No.730957 and 101017709,respectivelyfunding from the Kera-Solar project(Carl Zeiss Foundation)support at beamline P65 of the PETRA Ⅲ synchrotron(Deutsches Elektronen-Synchrotron DESY,Hamburg,Germany)is gratefully acknowledgedEduard Arzt(INM)for his continuing supportAndrea Jung(INM)for her support on ICP-OES measurementsthe support from the Karlsruhe Nano Micro Facility(KNMF,www.knmf.kit.edu),a Helmholtz research infrastructure at Karlsruhe Institute of Technology(KIT,www.kit.du).
文摘P2-type layered oxides with the general Na-deficient composition Na_(x)TMO_(2)(x<1,TM:transition metal)are a promising class of cathode materials for sodium-ion batteries.The open Na+transport pathways present in the structure lead to low diffusion barriers and enable high charge/discharge rates.However,a phase transition from P2 to O2 structure occurring above 4.2 V and metal dissolution at low potentials upon discharge results in rapid capacity degradation.In this work,we demonstrate the positive effect of configurational entropy on the stability of the crystal structure during battery operation.Three different compositions of layered P2-type oxides were synthesized by solid-state chemistry,Na_(0.67)(Mn_(0.55)Ni_(0.21)Co_(0.24))O_(2),Na_(0.67)(Mn_(0.45)Ni_(0.18)Co_(0.24)Ti_(0.1)Mg_(0.03))O_(2) and Na_(0.67)(Mn_(0.45)Ni_(0.18)Co_(0.18)Ti_(0.1)Mg_(0.03)Al_(0.04)Fe_(0.02))O_(2) with low,medium and high configurational entropy,respectively.The high-entropy cathode material shows lower structural transformation and Mn dissolution upon cycling in a wide voltage range from 1.5 to 4.6 V.Advanced operando techniques and post-mortem analysis were used to probe the underlying reaction mechanism thoroughly.Overall,the high-entropy strategy is a promising route for improving the electrochemical performance of P2 layered oxide cathodes for advanced sodium-ion battery applications.
基金F Strauss acknowledges financial support from the Fonds der Chemischen Industrie(FCI)through a Liebig fellowship.This work was partially supported by BASF SE.
文摘This short perspective summarizes recent findings on the role of residual lithium present on the surface of layered Ni-rich oxide cathode materials in liquid-and solid-electrolyte based batteries,with emphasis placed on the carbonate species.Challenges and future research opportunities in the development of carbonate-containing protective nanocoatings for inorganic solid-state battery applications are also discussed.
基金This study was supported by BASF SE.F Strauss acknowledges financial support from the Fonds der Chemischen Industrie through a Liebig fellowship.
文摘Solid-state batteries(SSBs)are a promising next step in electrochemical energy storage but are plagued by a number of problems.In this study,we demonstrate the recurring issue of mechanical degradation because of volume changes in layered Ni-rich oxide cathode materials in thiophosphate-based SSBs.Specifically,we explore superionic solid electrolytes(SEs)of different crystallinity,namely glassy 1.5Li_(2)S-0.5P_(2)S_(5)-LiI and argyrodite Li_(6)PS_(5)Cl,with emphasis on how they affect the cyclability of slurry-cast cathodes with NCM622(60%Ni)or NCM851005(85%Ni).The application of a combination of ex situ and in situ analytical techniques helped to reveal the benefits of using a SE with a low Young’s modulus.Through a synergistic interplay of(electro)chemical and(chemo)mechanical effects,the glassy SE employed in this work was able to achieve robust and stable interfaces,enabling intimate contact with the cathode material while at the same time mitigating volume changes.Our results emphasize the importance of considering chemical,electrochemical,and mechanical properties to realize long-term cycling performance in high-loading SSBs.
基金supported by BASF SEfunding by the German Research Foundation(DFG)under project ID 390874152(POLiS Cluster of Excellence)。
文摘O3-type layered oxide cathodes,such as NaNi_(0.5)Mn_(0.5)O_(2),have garnered significant attention due to their high theoretical specific capacity while using abundant and low-cost sodium as intercalation species.Unlike the lithium analog(LiNiO_(2)),NaNiO_(2)(NNO)exhibits poor electrochemical performance resulting from structural instability and inferior Coulomb efficiency.To enhance its cyclability for practical application,NNO was modified by titanium substitution to yield the O3-type NaNi_(0.9)Ti_(0.1)O_(2)(NNTO),which was successfully synthesized for the first time via a solid-state reaction.The mechanism behind its superior performance in comparison to that of similar materials is examined in detail using a variety of characterization techniques.NNTO delivers a specific discharge capacity of∼190 mAh g^(−1)and exhibits good reversibility,even in the presence of multiple phase transitions during cycling in a potential window of 2.0−4.2 V vs.Na^(+)/Na.This behavior can be attributed to the substituent,which helps maintain a larger interslab distance in the Na-deficient phases and to mitigate Jahn–Teller activity by reducing the average oxidation state of nickel.However,volume collapse at high potentials and irreversible lattice oxygen loss are still detrimental to the NNTO.Nevertheless,the performance can be further enhanced through coating and doping strategies.This not only positions NNTO as a promising next-generation cathode material,but also serves as inspiration for future research directions in the field of high-energy-density Na-ion batteries.
