To search for new cathode materials with high energy density of Lithium-ion batteries(LIBs) is one of the most challenging issues. Vanadium pentoxide(V2 O5) with high theoretical specific capacity is believed to be a ...To search for new cathode materials with high energy density of Lithium-ion batteries(LIBs) is one of the most challenging issues. Vanadium pentoxide(V2 O5) with high theoretical specific capacity is believed to be a promising candidate for the next generation cathode materials, yet still suffers from low lithium ion diffusion coefficient and poor electronic conductivity resulting in low cycling life and poor rate performances. Here, we report new large-scale carambola-like V2 O5 nanoflowers arrays anchored on microporous reed carbon as high performances LIBs cathode. Each individual pore space of the microporous reed carbon is like a hexagonal cylinder, and the area of each carbon wall is more than103 um2, which is favorable for the growth of V2 O5 nanostructure arrays. After hydrothermal, the largescale carambola-like V2 O5 nanoflowers arrays can directly grow on the surface of microporous carbon.Due to the novel composite structures, the V2 O5 nanoflowers arrays@microporous carbon stabilizes at273 mA h g^(-1) after 100 cycles at 0.2 C. When cycling at 1.0 C over 500 cycles, the capacity still maintains at 180 mAh g^(-1). The demonstrated approach in this work paves the way for the development of high rate capability and excellent cycling stability V2 O5-based cathode materials.展开更多
Self-standing carbon-based substrates with satisfied structural stability and property adjustability have promising applications in flexible lithium(Li)metal batteries(FLMBs).Current strategies for modifying carbon ma...Self-standing carbon-based substrates with satisfied structural stability and property adjustability have promising applications in flexible lithium(Li)metal batteries(FLMBs).Current strategies for modifying carbon materials are normally carried out on powder carbon,and very few of them are suitable for self-standing carbon substrates.Herein,a pore-forming strategy based on the redox chemistry of metallic oxide nanodots is developed to prepare two porous carbon substrates for anode and cathode.Starting with cotton cloth,the resulting hollow carbon fibers substrate with nanopores effectively prevents from Li dendrites formation and large volume change in lithium metal anode(LMA).Simulations indicate that the porous structure leads to homogeneous ion flux,Li-ion concentration,and electric field during Li deposition.Li symmetrical cell based on this substrate remains stable for 8300 h with an ultralow voltage hysteresis of 9 mV.Via a similar route,porous carbon cloth substrate is obtained for subsequently seeding V_(2)O_(5)nanowires to prepare the cathode.The assembled FLMBs pouch cell delivers a capacity of 8.2 mAh with a high capacity retention of~100%even under dramatic deformation.The demonstrated strategy has far-reaching potential in preparing free-standing porous carbon-based materials for flexible energy storage devices.展开更多
Since the electrode/electrolyte interface(EEI)is the main redox center of electrochemical processes,proper manipulation of the EEI microenvironment is crucial to stabilize interfacial behaviors.Here,a finger-paint met...Since the electrode/electrolyte interface(EEI)is the main redox center of electrochemical processes,proper manipulation of the EEI microenvironment is crucial to stabilize interfacial behaviors.Here,a finger-paint method is proposed to enable quick physical modification of glass-fiber separator without complicated chemical technology to modulate EEI of bilateral electrodes for aqueous zinc-ion batteries(ZIBs).An elaborate biochar derived from Aspergillus Niger is exploited as the modification agent of EEI,in which the multi-functional groups assist to accelerate Zn^(2+)desolvation and create a hydrophobic environment to homogenize the deposition behavior of Zn anode.Importantly,the finger-paint interface on separator can effectively protect cathodes from abnormal capacity fluctuation and/or rapid attenuation induced by H_(2)O molecular on the interface,which is demonstrated in modified MnO_(2),V_(2)O_(5),and KMn HCF-based cells.The as-proposed finger-paint method opens a new idea of bilateral interface engineering to facilitate the access to the practical application of the stable zinc electrochemistry.展开更多
V^(4+)-rich V_(2)O_(5)/carbon aerogel(V^(4+)-V_(2)O_(5)/CA)composites were synthesized as electrode materials for supercapacitors via in-situ hydrolysis-condensation processing.Carbon aerogel(CA)promotes the depositio...V^(4+)-rich V_(2)O_(5)/carbon aerogel(V^(4+)-V_(2)O_(5)/CA)composites were synthesized as electrode materials for supercapacitors via in-situ hydrolysis-condensation processing.Carbon aerogel(CA)promotes the deposition of amorphous vanadium oxide and catalyzes the crystallization of V^(4+)-rich V_(2)O_(5)nanosheets at much reduced temperature.With a uniform distribution of V_(2)O_(5)nanosheets in CA,the special structure provides a large specific area and reactive sites.CA also synergistically improves the electrical conductivity and structural integrity.In addition,rich V^(4+) would enhance the intrinsic electrical conductivity of V_(2)O_(5),promote ion diffusion and catalyze the electrochemical reactions.Consequently,V^(4+)-V_(2)O_(5)/CA exhibits much enhanced specific capacitance(405 F g^(-1) at 0.5 A g^(-1)),high energy density(56 W h kg^(-1) with a power density of 250 W kg^(-1))and long cycle life(96%capacitance retention after 40,000 cycles).展开更多
Flexible power sources featuring high-performance,prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices.However,many great challenges remain to be overcome...Flexible power sources featuring high-performance,prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices.However,many great challenges remain to be overcome,notably the design and fabrication of flexible electrodes with excellent electrochemical performance and matching them with safe and reliable electrolytes.Herein,a facile approach for preparing flexible electrodes,which employs carbon cloth derived from commercial cotton cloth as the substrate of cathode and a flexible anode,is proposed and investigated.The promising cathode(NVPOF@FCC)with high conductivity and outstanding flexibility is prepared by efficiently coating Na_(3)V_(2)(PO_(4))_(2)O_(2)F(NVPOF)on flexible carbon cloth(FCC),which exhibits remarkable electrochemical performance and the significantly improved reaction kinetics.More importantly,a novel flexible quasi-solid-state sodium-ion full battery(QSFB)is feasibly assembled by sandwiching a P(VDF-HFP)-NaClO_(4) gel-polymer electrolyte film between the advanced NVPOF@FCC cathode and FCC anode.And the QSFBs are further evaluated in flexible pouch cells,which not only demonstrates excellent energy-storage performance in aspect of great cycling stability and high-rate capability,but also impressive flexibility and safety.This work offers a feasible and effective strategy for the design of flexible electrodes,paving the way for the progression of practical and sustainable flexible batteries.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 51922038 and 51672078)Hunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Independent Research Project (No. 71675004)+1 种基金Hunan Youth Talents (2016RS3025)Hunan Natural Science Foundation (2016JJ3123)。
文摘To search for new cathode materials with high energy density of Lithium-ion batteries(LIBs) is one of the most challenging issues. Vanadium pentoxide(V2 O5) with high theoretical specific capacity is believed to be a promising candidate for the next generation cathode materials, yet still suffers from low lithium ion diffusion coefficient and poor electronic conductivity resulting in low cycling life and poor rate performances. Here, we report new large-scale carambola-like V2 O5 nanoflowers arrays anchored on microporous reed carbon as high performances LIBs cathode. Each individual pore space of the microporous reed carbon is like a hexagonal cylinder, and the area of each carbon wall is more than103 um2, which is favorable for the growth of V2 O5 nanostructure arrays. After hydrothermal, the largescale carambola-like V2 O5 nanoflowers arrays can directly grow on the surface of microporous carbon.Due to the novel composite structures, the V2 O5 nanoflowers arrays@microporous carbon stabilizes at273 mA h g^(-1) after 100 cycles at 0.2 C. When cycling at 1.0 C over 500 cycles, the capacity still maintains at 180 mAh g^(-1). The demonstrated approach in this work paves the way for the development of high rate capability and excellent cycling stability V2 O5-based cathode materials.
基金supported by NSFC(22035001,21574018,51433003)the National Science and Engineering Council of Canada,and the Fundamental Research Funds for the Central Universities(2412019ZD002)。
文摘Self-standing carbon-based substrates with satisfied structural stability and property adjustability have promising applications in flexible lithium(Li)metal batteries(FLMBs).Current strategies for modifying carbon materials are normally carried out on powder carbon,and very few of them are suitable for self-standing carbon substrates.Herein,a pore-forming strategy based on the redox chemistry of metallic oxide nanodots is developed to prepare two porous carbon substrates for anode and cathode.Starting with cotton cloth,the resulting hollow carbon fibers substrate with nanopores effectively prevents from Li dendrites formation and large volume change in lithium metal anode(LMA).Simulations indicate that the porous structure leads to homogeneous ion flux,Li-ion concentration,and electric field during Li deposition.Li symmetrical cell based on this substrate remains stable for 8300 h with an ultralow voltage hysteresis of 9 mV.Via a similar route,porous carbon cloth substrate is obtained for subsequently seeding V_(2)O_(5)nanowires to prepare the cathode.The assembled FLMBs pouch cell delivers a capacity of 8.2 mAh with a high capacity retention of~100%even under dramatic deformation.The demonstrated strategy has far-reaching potential in preparing free-standing porous carbon-based materials for flexible energy storage devices.
基金financial support from the National Natural Science Foundation of China (21571080 and 52202253)the Natural Science Foundation of Jiangsu Province (BK20220914)+2 种基金Project funded by China Postdoctoral Science Foundation (2022M721593)the Jiangsu Funding Program for Excellent Postdoctoral Talent (2022ZB193)the financial support from International Center of Future Science,Jilin University,Changchun,P.R.China (ICFS Seed Funding for Young Researchers)。
文摘Since the electrode/electrolyte interface(EEI)is the main redox center of electrochemical processes,proper manipulation of the EEI microenvironment is crucial to stabilize interfacial behaviors.Here,a finger-paint method is proposed to enable quick physical modification of glass-fiber separator without complicated chemical technology to modulate EEI of bilateral electrodes for aqueous zinc-ion batteries(ZIBs).An elaborate biochar derived from Aspergillus Niger is exploited as the modification agent of EEI,in which the multi-functional groups assist to accelerate Zn^(2+)desolvation and create a hydrophobic environment to homogenize the deposition behavior of Zn anode.Importantly,the finger-paint interface on separator can effectively protect cathodes from abnormal capacity fluctuation and/or rapid attenuation induced by H_(2)O molecular on the interface,which is demonstrated in modified MnO_(2),V_(2)O_(5),and KMn HCF-based cells.The as-proposed finger-paint method opens a new idea of bilateral interface engineering to facilitate the access to the practical application of the stable zinc electrochemistry.
基金support from the National Natural Science Foundation of China(51872204,52072261,and 22011540379)Shanghai Sailing Program(21YF1430900)+2 种基金the National Key Research and Development Program of China(2017YFA0204600)Shanghai Social Development Science and Technology Project(20dz1201800)supported by the National Natural Science Foundation(1803256)。
文摘V^(4+)-rich V_(2)O_(5)/carbon aerogel(V^(4+)-V_(2)O_(5)/CA)composites were synthesized as electrode materials for supercapacitors via in-situ hydrolysis-condensation processing.Carbon aerogel(CA)promotes the deposition of amorphous vanadium oxide and catalyzes the crystallization of V^(4+)-rich V_(2)O_(5)nanosheets at much reduced temperature.With a uniform distribution of V_(2)O_(5)nanosheets in CA,the special structure provides a large specific area and reactive sites.CA also synergistically improves the electrical conductivity and structural integrity.In addition,rich V^(4+) would enhance the intrinsic electrical conductivity of V_(2)O_(5),promote ion diffusion and catalyze the electrochemical reactions.Consequently,V^(4+)-V_(2)O_(5)/CA exhibits much enhanced specific capacitance(405 F g^(-1) at 0.5 A g^(-1)),high energy density(56 W h kg^(-1) with a power density of 250 W kg^(-1))and long cycle life(96%capacitance retention after 40,000 cycles).
基金supported by the National Natural Science Foundation of China(No.91963118)Science Technology Program of Jilin Province(No.20200201066JC)+2 种基金Fundamental Research Funds for the Central Universities(No.2412020QD013)China Postdoctoral Science Foundation(No.2019M661187)the National Postdoctoral Program for Innovative Talents(BX20190064).
文摘Flexible power sources featuring high-performance,prominent flexibility and raised safety have received mounting attention in the area of wearable electronic devices.However,many great challenges remain to be overcome,notably the design and fabrication of flexible electrodes with excellent electrochemical performance and matching them with safe and reliable electrolytes.Herein,a facile approach for preparing flexible electrodes,which employs carbon cloth derived from commercial cotton cloth as the substrate of cathode and a flexible anode,is proposed and investigated.The promising cathode(NVPOF@FCC)with high conductivity and outstanding flexibility is prepared by efficiently coating Na_(3)V_(2)(PO_(4))_(2)O_(2)F(NVPOF)on flexible carbon cloth(FCC),which exhibits remarkable electrochemical performance and the significantly improved reaction kinetics.More importantly,a novel flexible quasi-solid-state sodium-ion full battery(QSFB)is feasibly assembled by sandwiching a P(VDF-HFP)-NaClO_(4) gel-polymer electrolyte film between the advanced NVPOF@FCC cathode and FCC anode.And the QSFBs are further evaluated in flexible pouch cells,which not only demonstrates excellent energy-storage performance in aspect of great cycling stability and high-rate capability,but also impressive flexibility and safety.This work offers a feasible and effective strategy for the design of flexible electrodes,paving the way for the progression of practical and sustainable flexible batteries.
