Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)ca...Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li anode.To get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_8.The introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode simultaneously.The minor Se substitution compensates the decrease in kinetic due to the decreased solubility of LiPSs.In this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,respectively.Besides,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode loading.It makes more sense to guide the electrolyte design for practical Li-S batteries.展开更多
The metallic lithium(Li)is considered as the most promising anode material for high-e nergy batteries.Nevertheless,the uncon trollable growth of Li den drite and un stable electrolyte/electrode in terface still hin de...The metallic lithium(Li)is considered as the most promising anode material for high-e nergy batteries.Nevertheless,the uncon trollable growth of Li den drite and un stable electrolyte/electrode in terface still hin der the developme nt of Li-based battery.In this work,a no vel strategy has been proposed to stabilize Li anode by in-situ polymerizing polypyrrole(PPy)layer on Ni foam(PPy@Ni foam)as an artificial protective layer.The PPy protective layer can effectively decrease the contact between Li metal and electrolyte during cycling.In addition,the morphology characterization shows that the PPy layer can help the even Li deposition undemeath the layer,leading to a dendrite-free Li anode.As a result,when deposited 2 mAh-cm-2 Li metal,the PPy@Ni foam can keep stable Coulombic efficiency(99%)during nearly 250 cycles,much better than the pure Ni foam(100 cycles).Even in the case of the Li capacity of 10 mAh-cm-2,the stable cycling performance for 60 cycles can still be achieved.Furthermore,when assembled with LiFePO4 material as the cathode for a full cell,the PPy@Ni foam can keep high capacity retention of 85.5%at 500 cycles.In our work,we provide a simple and effective method to enhanee the electrochemical performances of Li metal-based batteries,and reveal a new avenue to design three-dimensional(3D)metallic curre nt collector for protecting the Li metal ano de.展开更多
Lithium-ion batteries(LIBs)have been extensively used in electronic devices,electric vehicles,and energy storage systems due to their high energy density,environmental friendliness,and longevity.However,LIBs are sensi...Lithium-ion batteries(LIBs)have been extensively used in electronic devices,electric vehicles,and energy storage systems due to their high energy density,environmental friendliness,and longevity.However,LIBs are sensitive to environmental conditions and prone to thermal runaway(TR),fire,and even explosion under conditions of mechanical,electrical,and/or thermal abuse.These unpredictable hazardous consequences significantly limit the commercial applications of LIBs.Thus,these safety issues need to be urgently addressed.In this review,the TR mechanisms and fire characteristics of LIBs are systematically discussed.Battery thermal safety monitoring methods,including the traditional technologies such as tempera-ture,voltage,and gas sensors,as well as the latest new technologies such as optical fiber sensors and ultrasonic imaging,are summarized.A battery thermal management system(BTMS)based on various cooling methods and new insights into the BTMS are briefly presented.According to the fire characteristics of LIBs,nonaqueous and water-based fire extinguishing agents are comprehensively summarized and compared,and the concept of an intelligent fire protection system is discussed.Based on the analysis of the thermal safety issues for preventing possible TRs and for extinguishing an already uncontrollable fire,a complete set of solutions for the thermal safety of LIBs is proposed.In this review,integrated strategies for intelligent detection and fire suppression of LIBs are presented and can provide theoretical guidance for key material design and intel-lectual safety systems to promote wide application of LIBs.展开更多
基金supported by the National Natural Science Foundation of China(22075091)the Natural Science Foundation of Hubei Province(Grant No.2021CFA066)。
文摘Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li anode.To get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_8.The introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode simultaneously.The minor Se substitution compensates the decrease in kinetic due to the decreased solubility of LiPSs.In this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,respectively.Besides,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode loading.It makes more sense to guide the electrolyte design for practical Li-S batteries.
基金his work is supported by the National Natural Science Foundation of China(Nos.212731&21621091 and 21875195)the National Key Research and Development Program of China(No.2017YFB0102000)the Fundamental Research Funds for the Central Universities(No.20720190040).
文摘The metallic lithium(Li)is considered as the most promising anode material for high-e nergy batteries.Nevertheless,the uncon trollable growth of Li den drite and un stable electrolyte/electrode in terface still hin der the developme nt of Li-based battery.In this work,a no vel strategy has been proposed to stabilize Li anode by in-situ polymerizing polypyrrole(PPy)layer on Ni foam(PPy@Ni foam)as an artificial protective layer.The PPy protective layer can effectively decrease the contact between Li metal and electrolyte during cycling.In addition,the morphology characterization shows that the PPy layer can help the even Li deposition undemeath the layer,leading to a dendrite-free Li anode.As a result,when deposited 2 mAh-cm-2 Li metal,the PPy@Ni foam can keep stable Coulombic efficiency(99%)during nearly 250 cycles,much better than the pure Ni foam(100 cycles).Even in the case of the Li capacity of 10 mAh-cm-2,the stable cycling performance for 60 cycles can still be achieved.Furthermore,when assembled with LiFePO4 material as the cathode for a full cell,the PPy@Ni foam can keep high capacity retention of 85.5%at 500 cycles.In our work,we provide a simple and effective method to enhanee the electrochemical performances of Li metal-based batteries,and reveal a new avenue to design three-dimensional(3D)metallic curre nt collector for protecting the Li metal ano de.
基金the National Key Research and Development Program of China(2023YFB2406000)National Natural Science Foundation of China(No.52027816).
文摘Lithium-ion batteries(LIBs)have been extensively used in electronic devices,electric vehicles,and energy storage systems due to their high energy density,environmental friendliness,and longevity.However,LIBs are sensitive to environmental conditions and prone to thermal runaway(TR),fire,and even explosion under conditions of mechanical,electrical,and/or thermal abuse.These unpredictable hazardous consequences significantly limit the commercial applications of LIBs.Thus,these safety issues need to be urgently addressed.In this review,the TR mechanisms and fire characteristics of LIBs are systematically discussed.Battery thermal safety monitoring methods,including the traditional technologies such as tempera-ture,voltage,and gas sensors,as well as the latest new technologies such as optical fiber sensors and ultrasonic imaging,are summarized.A battery thermal management system(BTMS)based on various cooling methods and new insights into the BTMS are briefly presented.According to the fire characteristics of LIBs,nonaqueous and water-based fire extinguishing agents are comprehensively summarized and compared,and the concept of an intelligent fire protection system is discussed.Based on the analysis of the thermal safety issues for preventing possible TRs and for extinguishing an already uncontrollable fire,a complete set of solutions for the thermal safety of LIBs is proposed.In this review,integrated strategies for intelligent detection and fire suppression of LIBs are presented and can provide theoretical guidance for key material design and intel-lectual safety systems to promote wide application of LIBs.
