Compared with solid metals,liquid metals are considered more promising cathodes for molten slat/oxide electrolysis due to their fascinating advantages,which include strong depolarization effect,strong alloying effect,...Compared with solid metals,liquid metals are considered more promising cathodes for molten slat/oxide electrolysis due to their fascinating advantages,which include strong depolarization effect,strong alloying effect,excellent selective separation,and low operating temperature.In this review,we briefly introduce the properties of the liquid metal cathodes and their selection rules,and then summarize development in liquid metal cathodes for molten salt electrolysis,specifically the extraction of Ti and separation of actinides and rare-earth metals in halide melts.We also review recent attractive progress in the preparation of liquid Ti alloys via molten oxide electrolysis by using liquid metal cathodes.Problems related to high-quality alloy production and large-scale applications are cited,and several research directions to further improve the quality of alloys are also discussed to realize the industrial applications of liquid metal cathodes.展开更多
A green and effective electrolytic process was developed to produce high-purity Mg metal using primary and secondary resources containing Mg O as a feedstock. The electrolysis of various Mg O resources was conducted u...A green and effective electrolytic process was developed to produce high-purity Mg metal using primary and secondary resources containing Mg O as a feedstock. The electrolysis of various Mg O resources was conducted using a Cu cathode in MgF2– LiF – KCl molten salt at 1043 K by applying an average current of 1.44 A for 12.5 h. The electrolysis of calcined North Korean magnesite and seawater Mg O clinker yielded Mg alloys of MgCu2and(Cu) phases with current efficiencies of 89.6–92.4%. The electrolysis of oxidized Mg O-C refractory brick, aged ferronickel slag, and ferronickel slag yielded Mg alloys of MgCu2and(Cu) phases with current efficiencies of 59.3–92.3%. The vacuum distillation of Mg alloys obtained was conducted at 1300 K for 10 h to produce high-purity Mg metal. After vacuum distillation, Mg metal with a purity of above 99.994% was obtained. Therefore, this study demonstrates the feasibility of the production of high-purity Mg metal from various Mg O resources using a novel electrolytic process with a Cu cathode, followed by vacuum distillation.展开更多
In this study,a novel Mg production process for producing high-purity Mg metal from dolomite was developed.When the electrolysis of calcined dolomite was conducted using Cu cathode and C anode in MgF_(2)–LiF molten s...In this study,a novel Mg production process for producing high-purity Mg metal from dolomite was developed.When the electrolysis of calcined dolomite was conducted using Cu cathode and C anode in MgF_(2)–LiF molten salt at 1083–1173 K by applying an average current of 1.42–1.46 A for 9.50–21.0 h,the current efficiency of 66.4–88.6%was obtained.The produced Mg alloys consisted of MgCu_(2)and Cu(Mg)or MgCu_(2)and CuMg_(2)phases,depending on the Mg concentration in the Mg alloy.When the electrolysis of calcined dolomite was conducted in MgF_(2)–LiF–CaF_(2)molten salt at 1083 K,the current efficiency was 40.9–71.4%,owing to undesired reactions such as electroreduction of Ca^(2+)or/and CO_(3)^(2−)ions.Meanwhile,the current efficiency increased from 40.9%to 63.2%by utilizing a Pt anode,because the occurrence of CO_(3)^(2−)ions in the molten salt was prevented.After vacuum distillation of the obtained Mg alloys at 1300 K for 10 h,Mg metal with a purity of 99.9996–99.9998%was produced.Therefore,the feasibility of this novel process for the production of high-purity Mg metal from dolomite was demonstrated.展开更多
Irreversible reductive insertion of Zn2+transforms Mn3O4 such that the resulting Zn0.2Mn3O4 exhibits highly reversible storage properties of chloride ions,thus rendering Zn0.2Mn3O4 an excellent cathode of aqueous dual...Irreversible reductive insertion of Zn2+transforms Mn3O4 such that the resulting Zn0.2Mn3O4 exhibits highly reversible storage properties of chloride ions,thus rendering Zn0.2Mn3O4 an excellent cathode of aqueous dual-ion batteries.With Zn2+trapped,Zn0.2Mn3O4 delivers the chloride-storage capacity over 200 mAh/g at an average potential of 1.6 V vs Zn2+/Zn by reversibly forming a new ionic compound equivalent to Zn0.2Mn3O4Cl1.7.Electrochemical quartz crystal microbalance results suggest chloride as the primary charge carrier in the reversible oxidative anion insertion.The Mn3O4 anion-hosting cathode couples with Zn metal anode in a full-cell dual-ion battery,demonstrating stable cycling in practical pouch cells with an energy density of 150 Wh/kg based on the mass of both electrodes.展开更多
Lithium metal batteries (LMBs) show great potential in delivering high energy density (>500 Wh/kg) with cycling [1]. The cycling life of LMBs is mainly improved by regulating the composition and structure of solid/...Lithium metal batteries (LMBs) show great potential in delivering high energy density (>500 Wh/kg) with cycling [1]. The cycling life of LMBs is mainly improved by regulating the composition and structure of solid/cathode electrolyte interphase(SEI/CEI) with electrolytes [2]. However, both Li anode and transition metal oxide cathode have high interfacial reactivity at extreme voltages, which highly needs compatible electrolytes.Recently, localized high-concentration electrolytes (LHCEs) have promisingly stabilized the dual electrodes of high-voltage LMBs[3].展开更多
The electrochemistry of cathode materials for sodium-ion batteries differs significantly from lithium-ion batteries and offers distinct advantages.Overall,the progress of commercializing sodium-ion batteries is curren...The electrochemistry of cathode materials for sodium-ion batteries differs significantly from lithium-ion batteries and offers distinct advantages.Overall,the progress of commercializing sodium-ion batteries is currently impeded by the inherent inefficiencies exhibited by these cathode materials,which include insufficient conductivity,slow kinetics,and substantial volume changes throughout the process of intercalation and deintercalation cycles.Consequently,numerous methodologies have been utilized to tackle these challenges,encompassing structural modulation,surface modification,and elemental doping.This paper aims to highlight fundamental principles and strategies for the development of sodium transition metal oxide cathodes.Specifically,it emphasizes the role of various elemental doping techniques in initiating anionic redox reactions,improving cathode stability,and enhancing the operational voltage of these cathodes,aiming to provide readers with novel perspectives on the design of sodium metal oxide cathodes through the doping approach,as well as address the current obstacles that can be overcome/alleviated through these dopant strategies.展开更多
Cu-Li battery with Cu metal cathode and Li metal anode is a candidate for next-generation energy storage system.While self-discharge of the battery can be suppressed with an anion exchange membrane,the voltage polariz...Cu-Li battery with Cu metal cathode and Li metal anode is a candidate for next-generation energy storage system.While self-discharge of the battery can be suppressed with an anion exchange membrane,the voltage polarization depends strongly on the electrolyte.Specifically,when an electrolyte with 3 M LiTFSI(lithium bis(trifluoromethanesulfonyl)imide)in dimethyl carbonate(DMC)is used,overpotential increases with cycling.In this work,we reveal why the voltage polarization changes,and reduce and stabilize it by replacing DMC solvent with a mixed solvent composed of dimethoxyethane(DME)and propylene carbonate(PC).The new electrolyte has higher ionic conductivity and stable solvation structure with more free TFSI-anions upon cycling,which also facilitates uniform plating of metal ions on the metal electrodes.These characteristics enable a stable Cu-Li battery with minimal change in overpotential for more than 1500 cycles at a current density of 2 m A cm^(-2).展开更多
Research on the chemistry of high-energy-density transition metal oxide cathodes(TMOCs)is at the forefront in the pursuit of lithium-ion batteries with increased energy density.As a critical component of these cathode...Research on the chemistry of high-energy-density transition metal oxide cathodes(TMOCs)is at the forefront in the pursuit of lithium-ion batteries with increased energy density.As a critical component of these cathodes,binders not only glue cathode active material particles and conducting carbons together and to current collectors but also play pivotal roles in building multiscale compatible interphases between electrolytes and cathodes.In this review,we outline several vital design considerations of high-voltage binders,several of which are already present in traditional binder design that need to be highlighted,and systematically reveal the chemistry and mechanisms underpinning such binders for in-depth understanding.Further optimization of the design of polymer binders to improve battery performance is also discussed.Finally,perspec-tives regarding the future rational design and promising research opportunities of state-of-the-art binders for high-voltage TMOCs are presented.展开更多
Plasma immersion ion implantation （PI） overcomes the direct exposure limit of traditional beam- line ion implantation, and is suitable for the treatment of complex work-piece with large size. Pm technology is often ...Plasma immersion ion implantation （PI） overcomes the direct exposure limit of traditional beam- line ion implantation, and is suitable for the treatment of complex work-piece with large size. Pm technology is often used for surface modification of metal, plastics and ceramics. Based on the requirement of surface modification of large size insulating material, a composite full-directional PHI device based on RF plasma source and metal plasma source is developed in this paper. This device can not only realize gas ion implantation, but also can realize metal ion implantation, and can also realize gas ion mixing with metal ions injection. This device has two metal plasma sources and each metal source contains three cathodes. Under the condition of keeping the vacuum unchanged, the cathode can be switched freely. The volume of the vacuum chamber is about 0.94 m3, and maximum vacuum degree is about 5 x10-4 Pa. The density of RF plasma in homogeneous region is about 109 cm-3, and plasma density in the ion implantation region is about 101x cm-3. This device can be used for large-size sample material PHI treatment, the maximum size of the sample diameter up to 400 mm. The experimental results show that the plasma discharge in the device is stable and can run for a long time. It is suitable for surface treatment of insulating materials.展开更多
The intensities of fluorescence spectral lines of Ca atoms and Sr atoms in two different hollow cathode lamps （HCLs） are measured by element-balance-detection technology. In the wavelength range of 350–750 nm in th...The intensities of fluorescence spectral lines of Ca atoms and Sr atoms in two different hollow cathode lamps （HCLs） are measured by element-balance-detection technology. In the wavelength range of 350–750 nm in the visible spectral region, using the individual strongest line （Ca 422.67 nm, Sr 460.73 nm） as the bench mark, the population ratios between the excited states of Ca atoms and Sr atoms are calculated by rate equations and the spontaneous transition probabilities. The HCLs with populations at excited states can be used to realize the frequency stabilization reference of the laser frequency standard.展开更多
Layered Mn-based oxides are one of the promising cathode materials for potassium-ion batteries(KIBs)owing to their high theoretical capacities,abundant material supply,and simple synthesis method.However,the structura...Layered Mn-based oxides are one of the promising cathode materials for potassium-ion batteries(KIBs)owing to their high theoretical capacities,abundant material supply,and simple synthesis method.However,the structural deterioration resulting from the Jahn-Teller effect of Mn ions hinders their further development in KIBs.Herein,a novel Mn-based layered oxide,K_(0.54)Mn_(0.78)Mg_(0.22)O_(2),is successfully designed and fabricated as KIBs cathode for the first time.It delivers smooth charging/discharging curves with high specific capacity of 132.4 mAh·g^(‒1)at 20 mA·g^(‒1)and good high-rate cycling stability with a capacity retention of 84%over 100 cycles at 200 mA·g^(‒1).Combining in-situ X-ray diffraction(XRD)and ex-situ X-ray photoelectron spectroscopy(XPS)analysis,the storage of K-ions by K_(0.54)Mn_(0.78)Mg_(0.22)O_(2)is revealed to be a solid-solution processes with reversible slip of the crystal lattice.The studies suggest that the rational doping of inactive Mg2+can effectively suppress the Jahn-Teller effect and provide outstanding structure stability.This work deepens the understanding of the structural evolution of Mn-based layered materials doped with inactive materials during de/potassiation processes.展开更多
基金the National Natural Science Foundation of China(Nos.51725401 and 51904030)the Fundamental Research Funds for the Cental Universities(No.FRF-TP-18-003C2).
文摘Compared with solid metals,liquid metals are considered more promising cathodes for molten slat/oxide electrolysis due to their fascinating advantages,which include strong depolarization effect,strong alloying effect,excellent selective separation,and low operating temperature.In this review,we briefly introduce the properties of the liquid metal cathodes and their selection rules,and then summarize development in liquid metal cathodes for molten salt electrolysis,specifically the extraction of Ti and separation of actinides and rare-earth metals in halide melts.We also review recent attractive progress in the preparation of liquid Ti alloys via molten oxide electrolysis by using liquid metal cathodes.Problems related to high-quality alloy production and large-scale applications are cited,and several research directions to further improve the quality of alloys are also discussed to realize the industrial applications of liquid metal cathodes.
基金supported by the Korea Evaluation Institute of Industrial Technology funded by the Korean Ministry of Industry in Korea (Project No.:20000970, 20–9805)Basic Research Project (22–3803) of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Science and ICT of Korea。
文摘A green and effective electrolytic process was developed to produce high-purity Mg metal using primary and secondary resources containing Mg O as a feedstock. The electrolysis of various Mg O resources was conducted using a Cu cathode in MgF2– LiF – KCl molten salt at 1043 K by applying an average current of 1.44 A for 12.5 h. The electrolysis of calcined North Korean magnesite and seawater Mg O clinker yielded Mg alloys of MgCu2and(Cu) phases with current efficiencies of 89.6–92.4%. The electrolysis of oxidized Mg O-C refractory brick, aged ferronickel slag, and ferronickel slag yielded Mg alloys of MgCu2and(Cu) phases with current efficiencies of 59.3–92.3%. The vacuum distillation of Mg alloys obtained was conducted at 1300 K for 10 h to produce high-purity Mg metal. After vacuum distillation, Mg metal with a purity of above 99.994% was obtained. Therefore, this study demonstrates the feasibility of the production of high-purity Mg metal from various Mg O resources using a novel electrolytic process with a Cu cathode, followed by vacuum distillation.
基金supported by the National Research Councile of Science and Technology funded by the Korean Ministry of Industry in Korea(Project Nos.:1711173260,22-3803)the Korea Evaluation Institute of Industrial Technology funded by the Korean Ministry of Industry in Korea(Project Nos.:1415179713,20011157).
文摘In this study,a novel Mg production process for producing high-purity Mg metal from dolomite was developed.When the electrolysis of calcined dolomite was conducted using Cu cathode and C anode in MgF_(2)–LiF molten salt at 1083–1173 K by applying an average current of 1.42–1.46 A for 9.50–21.0 h,the current efficiency of 66.4–88.6%was obtained.The produced Mg alloys consisted of MgCu_(2)and Cu(Mg)or MgCu_(2)and CuMg_(2)phases,depending on the Mg concentration in the Mg alloy.When the electrolysis of calcined dolomite was conducted in MgF_(2)–LiF–CaF_(2)molten salt at 1083 K,the current efficiency was 40.9–71.4%,owing to undesired reactions such as electroreduction of Ca^(2+)or/and CO_(3)^(2−)ions.Meanwhile,the current efficiency increased from 40.9%to 63.2%by utilizing a Pt anode,because the occurrence of CO_(3)^(2−)ions in the molten salt was prevented.After vacuum distillation of the obtained Mg alloys at 1300 K for 10 h,Mg metal with a purity of 99.9996–99.9998%was produced.Therefore,the feasibility of this novel process for the production of high-purity Mg metal from dolomite was demonstrated.
文摘Irreversible reductive insertion of Zn2+transforms Mn3O4 such that the resulting Zn0.2Mn3O4 exhibits highly reversible storage properties of chloride ions,thus rendering Zn0.2Mn3O4 an excellent cathode of aqueous dual-ion batteries.With Zn2+trapped,Zn0.2Mn3O4 delivers the chloride-storage capacity over 200 mAh/g at an average potential of 1.6 V vs Zn2+/Zn by reversibly forming a new ionic compound equivalent to Zn0.2Mn3O4Cl1.7.Electrochemical quartz crystal microbalance results suggest chloride as the primary charge carrier in the reversible oxidative anion insertion.The Mn3O4 anion-hosting cathode couples with Zn metal anode in a full-cell dual-ion battery,demonstrating stable cycling in practical pouch cells with an energy density of 150 Wh/kg based on the mass of both electrodes.
文摘Lithium metal batteries (LMBs) show great potential in delivering high energy density (>500 Wh/kg) with cycling [1]. The cycling life of LMBs is mainly improved by regulating the composition and structure of solid/cathode electrolyte interphase(SEI/CEI) with electrolytes [2]. However, both Li anode and transition metal oxide cathode have high interfacial reactivity at extreme voltages, which highly needs compatible electrolytes.Recently, localized high-concentration electrolytes (LHCEs) have promisingly stabilized the dual electrodes of high-voltage LMBs[3].
基金the National Natural Science Foundation of China(No.22250710676)the Fujian Provice Super 100 Talents Program,and the Fujian Provice 100 Talents Program,Fujian Provice Minjiang Scholar Program.
文摘The electrochemistry of cathode materials for sodium-ion batteries differs significantly from lithium-ion batteries and offers distinct advantages.Overall,the progress of commercializing sodium-ion batteries is currently impeded by the inherent inefficiencies exhibited by these cathode materials,which include insufficient conductivity,slow kinetics,and substantial volume changes throughout the process of intercalation and deintercalation cycles.Consequently,numerous methodologies have been utilized to tackle these challenges,encompassing structural modulation,surface modification,and elemental doping.This paper aims to highlight fundamental principles and strategies for the development of sodium transition metal oxide cathodes.Specifically,it emphasizes the role of various elemental doping techniques in initiating anionic redox reactions,improving cathode stability,and enhancing the operational voltage of these cathodes,aiming to provide readers with novel perspectives on the design of sodium metal oxide cathodes through the doping approach,as well as address the current obstacles that can be overcome/alleviated through these dopant strategies.
基金supported by a Research Matching Grant Scheme(PJ9229008)by the government of Hong Kong Special Administrative Region。
文摘Cu-Li battery with Cu metal cathode and Li metal anode is a candidate for next-generation energy storage system.While self-discharge of the battery can be suppressed with an anion exchange membrane,the voltage polarization depends strongly on the electrolyte.Specifically,when an electrolyte with 3 M LiTFSI(lithium bis(trifluoromethanesulfonyl)imide)in dimethyl carbonate(DMC)is used,overpotential increases with cycling.In this work,we reveal why the voltage polarization changes,and reduce and stabilize it by replacing DMC solvent with a mixed solvent composed of dimethoxyethane(DME)and propylene carbonate(PC).The new electrolyte has higher ionic conductivity and stable solvation structure with more free TFSI-anions upon cycling,which also facilitates uniform plating of metal ions on the metal electrodes.These characteristics enable a stable Cu-Li battery with minimal change in overpotential for more than 1500 cycles at a current density of 2 m A cm^(-2).
基金This work was financially supported by the NSFC-Shandong Joint Fund(U1706229)the Science Foundation for the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010603)+1 种基金the National Natural Science Foundation of China(51803230)the Qingdao Key Laboratory of Solar Energy Utilization and Energy Storage Technology.
文摘Research on the chemistry of high-energy-density transition metal oxide cathodes(TMOCs)is at the forefront in the pursuit of lithium-ion batteries with increased energy density.As a critical component of these cathodes,binders not only glue cathode active material particles and conducting carbons together and to current collectors but also play pivotal roles in building multiscale compatible interphases between electrolytes and cathodes.In this review,we outline several vital design considerations of high-voltage binders,several of which are already present in traditional binder design that need to be highlighted,and systematically reveal the chemistry and mechanisms underpinning such binders for in-depth understanding.Further optimization of the design of polymer binders to improve battery performance is also discussed.Finally,perspec-tives regarding the future rational design and promising research opportunities of state-of-the-art binders for high-voltage TMOCs are presented.
文摘Plasma immersion ion implantation （PI） overcomes the direct exposure limit of traditional beam- line ion implantation, and is suitable for the treatment of complex work-piece with large size. Pm technology is often used for surface modification of metal, plastics and ceramics. Based on the requirement of surface modification of large size insulating material, a composite full-directional PHI device based on RF plasma source and metal plasma source is developed in this paper. This device can not only realize gas ion implantation, but also can realize metal ion implantation, and can also realize gas ion mixing with metal ions injection. This device has two metal plasma sources and each metal source contains three cathodes. Under the condition of keeping the vacuum unchanged, the cathode can be switched freely. The volume of the vacuum chamber is about 0.94 m3, and maximum vacuum degree is about 5 x10-4 Pa. The density of RF plasma in homogeneous region is about 109 cm-3, and plasma density in the ion implantation region is about 101x cm-3. This device can be used for large-size sample material PHI treatment, the maximum size of the sample diameter up to 400 mm. The experimental results show that the plasma discharge in the device is stable and can run for a long time. It is suitable for surface treatment of insulating materials.
基金supported by the National Natural Science Foundation of China(No.91436210)
文摘The intensities of fluorescence spectral lines of Ca atoms and Sr atoms in two different hollow cathode lamps （HCLs） are measured by element-balance-detection technology. In the wavelength range of 350–750 nm in the visible spectral region, using the individual strongest line （Ca 422.67 nm, Sr 460.73 nm） as the bench mark, the population ratios between the excited states of Ca atoms and Sr atoms are calculated by rate equations and the spontaneous transition probabilities. The HCLs with populations at excited states can be used to realize the frequency stabilization reference of the laser frequency standard.
基金This work was supported by the National Natural Science Foundation of China(Nos.51972030 and 51772030)the S&T Major Project of Inner Mongolia Autonomous Region in China(2020ZD0018)+1 种基金Beijing Outstanding Young Scientists Program(BJJWZYJH01201910007023)Guangdong Key Laboratory of Battery Safety(2019B121203008).
文摘Layered Mn-based oxides are one of the promising cathode materials for potassium-ion batteries(KIBs)owing to their high theoretical capacities,abundant material supply,and simple synthesis method.However,the structural deterioration resulting from the Jahn-Teller effect of Mn ions hinders their further development in KIBs.Herein,a novel Mn-based layered oxide,K_(0.54)Mn_(0.78)Mg_(0.22)O_(2),is successfully designed and fabricated as KIBs cathode for the first time.It delivers smooth charging/discharging curves with high specific capacity of 132.4 mAh·g^(‒1)at 20 mA·g^(‒1)and good high-rate cycling stability with a capacity retention of 84%over 100 cycles at 200 mA·g^(‒1).Combining in-situ X-ray diffraction(XRD)and ex-situ X-ray photoelectron spectroscopy(XPS)analysis,the storage of K-ions by K_(0.54)Mn_(0.78)Mg_(0.22)O_(2)is revealed to be a solid-solution processes with reversible slip of the crystal lattice.The studies suggest that the rational doping of inactive Mg2+can effectively suppress the Jahn-Teller effect and provide outstanding structure stability.This work deepens the understanding of the structural evolution of Mn-based layered materials doped with inactive materials during de/potassiation processes.
