Phosphate material LiMnPO4 is popular for its high energy density(697 W·h·kg^(-1))and safety.When LiMnPO_(4) crystal grows,the potential barrier along b and c axis is strong,which makes the crystal grow alon...Phosphate material LiMnPO4 is popular for its high energy density(697 W·h·kg^(-1))and safety.When LiMnPO_(4) crystal grows,the potential barrier along b and c axis is strong,which makes the crystal grow along b axis to form a one-dimensional chain structure.However,the main migration channel of lithium ions in olivine structure is plane(010).By shortening the growth in the direction of b axis and enhancing the diffusion along the directions of a and c,two-dimensional nanosheets that are more conducive to the migration of lithium ions are formed.The dosage of polyols is the key factor guiding the dispersion of the crystals to the(010)plane.X-ray diffraction(XRD),Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and other means are used to characterize the samples.After experiments,we found that when the ratio of polyol/water was 2:1,the morphology of the synthesized sample was 20–30 nm thick nanosheets,which had the best electrochemical performance.At 0.1C,the discharge specific capacity reaches 148.9 mA·h·g^(-1),still reaches 144.3 mA·h·g^(-1) at the 50th cycle.and there is still 112.5 mA·h·g^(-1) under high rate(5C).This is thanks to the good dispersion of the material in the direction of the crystal plane(010).This can solve the problem of low conductivity and ionic mobility of phosphate materials.展开更多
Lithium-sulfur batteries(LSBs)have a high theoretical capacity,which is considered as one of the most promising high-energy-density secondary batteries due to the double electrons reaction of sulfur.However,the shuttl...Lithium-sulfur batteries(LSBs)have a high theoretical capacity,which is considered as one of the most promising high-energy-density secondary batteries due to the double electrons reaction of sulfur.However,the shuttle effects of lithium polysulfides(Li PSs)and sluggish redox kinetics lead to their materials capacity loss and cycle stability deterioration,which restrains LSBs commercialization.Metallic compounds as additions can improve the electrochemical performance of the Li-S system,through the trap of Li PSs and accelerate the conversion of the soluble Li PSs.Among of them,the iron group elements(Fe,Ni,Co)-based compounds are the promising materials for the LSBs,due to their unique outer electronic structure and its tunable properties,low cost,abundant in the earth,environmental benignity,controllable and scalable prepared,and so on.In this review,we have made a summary for iron-based compounds to capture Li PSs according to lithium bond,sulfur bond and magnetic force.The type of iron-based compound including oxides,sulfides,nitrides,phosphides,carbides,and so on,and we have investigated the electrocatalytic mechanism of these materials.Besides,some improvement strategies are proposed,such as the engineering of the special micro/nanostructure,defect concentrations,band structures,and heterostructures.We hope to shed an in-depth light on the rationally design and fabrication of robust,commercial and stable materials for high-performance LSBs.展开更多
Heteroatom doped porous carbon materials have emerged as essential cathode material for metal-air battery systems in the context of soaring demands for clean energy conversion and storage.Herein,a three-dimensional ni...Heteroatom doped porous carbon materials have emerged as essential cathode material for metal-air battery systems in the context of soaring demands for clean energy conversion and storage.Herein,a three-dimensional nitrogen-doped carbon self-supported electrode(TNCSE)is fabricated through thermal treatment and acid activation of raw wood.The resulting TNCSE retains the hierarchical porous architecture of parent raw lumber and holds substantial defect sites and doped N sites in the carbon skeleton.Assembled as a cathode in the rechargeable zinc-air battery,the TNCSE exhibits a superior peak power density of 134.02 m W/cm^(2)and an energy density of 835.92 m Ah/g,significantly exceeding the ones reference commercial 20%Pt/C does.More strikingly,a limited performance decay of 1.47%after an ultra long-period(500 h)cycle is also achieved on the TNCSE.This work could offer a green and cost-save approach for rationally converting biomass into a robust self-supporting cathode material for a rechargeable zinc-air battery.展开更多
With advantages of low costs and high energy density,Li–S batteries are considered as one of the most promising energy storage devices.However,Li_(2)S_(2) with a high dissociation energy and insulative properties is ...With advantages of low costs and high energy density,Li–S batteries are considered as one of the most promising energy storage devices.However,Li_(2)S_(2) with a high dissociation energy and insulative properties is hard to convert into Li_(2)S,resulting in underutilization of sulfur capacity.Herein,Co-Mo_(2)C@C yolk–shell spheres as nanoreactors were designed to confront this challenge rationally.The Co-Mo_(2)C@C-induced Li_(2)S_(1/2) nucleation and growth in the three-dimensional process and the cathode produced more Li_(2)S after full discharge.Experimental studies and theoretical calculations reveal that the conversion barrier from Li_(2)S_(2) into Li_(2)S was lowered while the diffusion of lithium ions and electron transfer accelerated when using the Co-Mo_(2)C@C catalyst.Based on the above advantages,the Co-Mo_(2)C@C/S cathode exhibits a high reversible capacity and excellent cyclic stability,such as an initial specific capacity of 1200 mAh g^(−1) at 0.1 C with 709 mAh g^(−1) at 1.0 C after 1000 cycles with a low capacity fading rate of 0.04%per cycle.Even at high densities of 3.0 C and 5.0 C,the specific capacities are 647.6 and 557.7 mAh g^(−1) after 400 cycles,respectively.Impressively,it also shows ca.770 and 900 mAh g^(−1) at 0.2 C after 50 cycles with high sulfur loadings of 4.2 and 5.1 mg cm−2,respectively.The present work may provide new insights into the design of nanoreactors to promote Li_(2)S_(1/2) growth in a three-dimensional process and accelerate conversion from solid Li_(2)S_(2) to solid Li_(2)S in high performance Li–S batteries.展开更多
The uncontrolled growth of lithium dendrites and accumulation of"dead lithium"upon cycling are among the main obstacles that hinder the widespread application of lithium metal anodes.Herein,an ionic liquid(I...The uncontrolled growth of lithium dendrites and accumulation of"dead lithium"upon cycling are among the main obstacles that hinder the widespread application of lithium metal anodes.Herein,an ionic liquid(IL)consisting of 1-methyl-1-propylpiperidinium cation(Pp_(13)^+) and bis(fluorosulfonyl)imide anion(FSI^(-)),was chosen as the additive in propylene carbonate(PC)-based liquid electrolytes to circumvent the shortcoming of lithium metal anodes.The optimal 1%Pp_(13) FSI acts as the role of electrostatic shielding,lithiophobic effect and participating in the formation of solid electrolyte interface(SEI)layer with enhanced properties.The in-situ optical microscopy records that the addition of IL can effectively inhibit the growth of lithium dendrites and the corrosion of lithium anode.This study delivers an effective modification to optimize electrolytes for stable lithium metal batteries.展开更多
基金financial support from Natural Science Foundation of Guangdong Province(2018A030313423)Key Research and Development Program of Guangdong Province(2020B090919005)Pearl River Science and Technology New Star Project(201806010039).
文摘Phosphate material LiMnPO4 is popular for its high energy density(697 W·h·kg^(-1))and safety.When LiMnPO_(4) crystal grows,the potential barrier along b and c axis is strong,which makes the crystal grow along b axis to form a one-dimensional chain structure.However,the main migration channel of lithium ions in olivine structure is plane(010).By shortening the growth in the direction of b axis and enhancing the diffusion along the directions of a and c,two-dimensional nanosheets that are more conducive to the migration of lithium ions are formed.The dosage of polyols is the key factor guiding the dispersion of the crystals to the(010)plane.X-ray diffraction(XRD),Scanning electron microscopy(SEM),transmission electron microscopy(TEM)and other means are used to characterize the samples.After experiments,we found that when the ratio of polyol/water was 2:1,the morphology of the synthesized sample was 20–30 nm thick nanosheets,which had the best electrochemical performance.At 0.1C,the discharge specific capacity reaches 148.9 mA·h·g^(-1),still reaches 144.3 mA·h·g^(-1) at the 50th cycle.and there is still 112.5 mA·h·g^(-1) under high rate(5C).This is thanks to the good dispersion of the material in the direction of the crystal plane(010).This can solve the problem of low conductivity and ionic mobility of phosphate materials.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B090919005)the National Natural Science Foundation of China(U1801257,21975056,and 22179025)。
文摘Lithium-sulfur batteries(LSBs)have a high theoretical capacity,which is considered as one of the most promising high-energy-density secondary batteries due to the double electrons reaction of sulfur.However,the shuttle effects of lithium polysulfides(Li PSs)and sluggish redox kinetics lead to their materials capacity loss and cycle stability deterioration,which restrains LSBs commercialization.Metallic compounds as additions can improve the electrochemical performance of the Li-S system,through the trap of Li PSs and accelerate the conversion of the soluble Li PSs.Among of them,the iron group elements(Fe,Ni,Co)-based compounds are the promising materials for the LSBs,due to their unique outer electronic structure and its tunable properties,low cost,abundant in the earth,environmental benignity,controllable and scalable prepared,and so on.In this review,we have made a summary for iron-based compounds to capture Li PSs according to lithium bond,sulfur bond and magnetic force.The type of iron-based compound including oxides,sulfides,nitrides,phosphides,carbides,and so on,and we have investigated the electrocatalytic mechanism of these materials.Besides,some improvement strategies are proposed,such as the engineering of the special micro/nanostructure,defect concentrations,band structures,and heterostructures.We hope to shed an in-depth light on the rationally design and fabrication of robust,commercial and stable materials for high-performance LSBs.
基金the financial support from the National Natural Science Foundation of China(No.21905055)the start-up funding of Guangdong University of Technology(Nos.220413207 and 220418129)support from Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province。
文摘Heteroatom doped porous carbon materials have emerged as essential cathode material for metal-air battery systems in the context of soaring demands for clean energy conversion and storage.Herein,a three-dimensional nitrogen-doped carbon self-supported electrode(TNCSE)is fabricated through thermal treatment and acid activation of raw wood.The resulting TNCSE retains the hierarchical porous architecture of parent raw lumber and holds substantial defect sites and doped N sites in the carbon skeleton.Assembled as a cathode in the rechargeable zinc-air battery,the TNCSE exhibits a superior peak power density of 134.02 m W/cm^(2)and an energy density of 835.92 m Ah/g,significantly exceeding the ones reference commercial 20%Pt/C does.More strikingly,a limited performance decay of 1.47%after an ultra long-period(500 h)cycle is also achieved on the TNCSE.This work could offer a green and cost-save approach for rationally converting biomass into a robust self-supporting cathode material for a rechargeable zinc-air battery.
基金supported by the Key-Area Research and Development Program of Guangdong Province(grant no.2020B0909-19005)the National Natural Science Foundation of China(grant nos.21975056 and 22179025)+1 种基金The Major and Special Project in the Field of Intelligent Manufacturing of the Universities in Guangdong Province(grant no.2020ZDZX2067)the Natural Science Foundation of Huizhou University(grant no.HZU202004).
文摘With advantages of low costs and high energy density,Li–S batteries are considered as one of the most promising energy storage devices.However,Li_(2)S_(2) with a high dissociation energy and insulative properties is hard to convert into Li_(2)S,resulting in underutilization of sulfur capacity.Herein,Co-Mo_(2)C@C yolk–shell spheres as nanoreactors were designed to confront this challenge rationally.The Co-Mo_(2)C@C-induced Li_(2)S_(1/2) nucleation and growth in the three-dimensional process and the cathode produced more Li_(2)S after full discharge.Experimental studies and theoretical calculations reveal that the conversion barrier from Li_(2)S_(2) into Li_(2)S was lowered while the diffusion of lithium ions and electron transfer accelerated when using the Co-Mo_(2)C@C catalyst.Based on the above advantages,the Co-Mo_(2)C@C/S cathode exhibits a high reversible capacity and excellent cyclic stability,such as an initial specific capacity of 1200 mAh g^(−1) at 0.1 C with 709 mAh g^(−1) at 1.0 C after 1000 cycles with a low capacity fading rate of 0.04%per cycle.Even at high densities of 3.0 C and 5.0 C,the specific capacities are 647.6 and 557.7 mAh g^(−1) after 400 cycles,respectively.Impressively,it also shows ca.770 and 900 mAh g^(−1) at 0.2 C after 50 cycles with high sulfur loadings of 4.2 and 5.1 mg cm−2,respectively.The present work may provide new insights into the design of nanoreactors to promote Li_(2)S_(1/2) growth in a three-dimensional process and accelerate conversion from solid Li_(2)S_(2) to solid Li_(2)S in high performance Li–S batteries.
基金the Natural Science Foundation of Hainan Province(2019RC007)the National Natural Science Foundation of China(21805104,21606050,21905056,21905045,and U1801257)+3 种基金the Natural Science Foundation of Guangdong Province(2018A0303130239,2018A0303130223)Pearl River Science and Technology New Star Project(201806010039)the Start-up Research Foundation of Hainan University(KYQD(ZR)1908)Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province。
基金supported by the Key Research and Development Program of Guangdong Province(No.2020B090919005)the National Natural Science Foundation of China(Nos.21975056,52002079 and U1801257)Pearl River Science and Technology New Star Project(No.201806010039)。
文摘The uncontrolled growth of lithium dendrites and accumulation of"dead lithium"upon cycling are among the main obstacles that hinder the widespread application of lithium metal anodes.Herein,an ionic liquid(IL)consisting of 1-methyl-1-propylpiperidinium cation(Pp_(13)^+) and bis(fluorosulfonyl)imide anion(FSI^(-)),was chosen as the additive in propylene carbonate(PC)-based liquid electrolytes to circumvent the shortcoming of lithium metal anodes.The optimal 1%Pp_(13) FSI acts as the role of electrostatic shielding,lithiophobic effect and participating in the formation of solid electrolyte interface(SEI)layer with enhanced properties.The in-situ optical microscopy records that the addition of IL can effectively inhibit the growth of lithium dendrites and the corrosion of lithium anode.This study delivers an effective modification to optimize electrolytes for stable lithium metal batteries.
