因高能量密度和高能量转换效率,锂离子电池已被广泛应用于便携式电子设备和电动交通中。富锂层状结构氧化物以高达300 m Ah·g^-1的可逆容量成为能量密度350 Wh·kg^-1及以上动力锂离子电池的重要候选正极材料。但是,欲使这类...因高能量密度和高能量转换效率,锂离子电池已被广泛应用于便携式电子设备和电动交通中。富锂层状结构氧化物以高达300 m Ah·g^-1的可逆容量成为能量密度350 Wh·kg^-1及以上动力锂离子电池的重要候选正极材料。但是,欲使这类材料获得实际应用,就必须解决循环过程中结构衰退带来的一系列问题。本文重点介绍近几年来笔者所领导的研究组通过元素筛选实现材料的表面和体相掺杂,通过全新的结构设计稳定材料结构和性能方面的努力。同时,为使读者对国内外重要研究组在相关方面的研究进展也有所了解,我们也将从元素替代、结构一体化表面修饰(包括多层表面修饰和浓度梯度材料)、表面包覆和表面掺杂等方面介绍他们的重要研究成果。最后,将对该类材料的未来发展方向作出展望并给出我们的一些思考。展开更多
Drug-resistant bacteria,using their dense cell membranes as strong barrier,significantly reduce the efficacy of conventional antibacterial treatments.Phototriggered 2D catalytic nanomaterials have emerged as promising...Drug-resistant bacteria,using their dense cell membranes as strong barrier,significantly reduce the efficacy of conventional antibacterial treatments.Phototriggered 2D catalytic nanomaterials have emerged as promising candidates against drug-resistant bacteria by inducing membrane mechanical damage and generating reactive oxygen species(ROS).However,the practical antibacterial efficacy of typical 2D graphitic carbon nitride(g-C_(3)N_(4))is severely limited due to the low ROS production.Herein,we report an interfacial band-engineered lamellar heterojunctions(MnCN LHJs)through in situ Mn_(2)O_(3)growth on g-C_(3)N_(4).The charges generated in g-C_(3)N_(4)are stabilized by Mn_(2)O_(3),minimizing electron-hole recombination and boosting ROS production.Meanwhile,the photocatalytic effect of MnCN LHJs works synergistically with photothermal effects of Mn_(2)O_(3)to induce a robust“melee attack”against drug-resistant bacteria.High-resolution synchrotron radiation X-ray tomography directly visualized that MnCN LHJs possessed bacterial trapping capabilities,revealing their ability to induce mechanical damage to bacteria membrane for the first time.Additionally,MnCN LHJs can deplete endogenous glutathione,thereby enhancing ROS generation and weakening the bacterial antioxidant defense system.These combined effects achieve a remarkable bactericidal rate exceeding 98% against methicillin-resistant Staphylococcus aureus(MRSA).Notably,MnCN LHJs demonstrate prolonged retention at wound sites,helping to reduce inflammation and promote angiogenesis in infected wounds.This work not only advances interfacial band engineering approach to enhance the photocatalytic performance of g-C_(3)N_(4)but also underscores the significance of nanomaterial-bacteria interaction in design of next-generation antibacterial materials.展开更多
The continuous lithium consumption during cycling severely reduces the energy density of the lithium battery,and thus,lithium compensation is essential.Herein,Li_(x)C_(6)O_(6)(x=2,4)was proposed as an air-stable high-...The continuous lithium consumption during cycling severely reduces the energy density of the lithium battery,and thus,lithium compensation is essential.Herein,Li_(x)C_(6)O_(6)(x=2,4)was proposed as an air-stable high-efficiency sacrificial additive in the cathode to compensate for the lost lithium ions in solid-state lithium batteries.Below a delithiation(oxidation)potential as low as 3.8 V,Li_(2)C_(6)O_(6) can release most of its Li^(+)ions(294.8 mAh g^(−1) in theory).Similarly,Li_(4)C_(6)O_(6) is also characteristic of low oxidation potential and high delithiation capacity(547.8 mAh g^(−1) in theory).The feasibility of using Li_(x)C_(6)O_(6) as the self-sacrificial additive in the cathode was verified with the marked increase of the initial charge capacity of the Li||LiFePO_(4)(half)cells and the initial discharge capacity of Cu||LiFePO_(4)(full)cells,and the improved electrolyte/cathode interface stability and interface contact,in the solid-state poly(ethylene oxide)-lithium bis(trifluoromethane)sulfonimide(PEO-LiTFSI)electrolyte.In addition,the structure and delithiation of Li_(x)C_(6)O_(6) and the impacts of its decomposition product on the PEO-LiTFSI solid electrolyte were also evaluated on the basis of the comprehensive physical characterizations and the density functional theory(DFT)calculations.These findings open a new avenue for elevating the energy density and/or elongate the lifespan of the solid-state secondary batteries.展开更多
文摘因高能量密度和高能量转换效率,锂离子电池已被广泛应用于便携式电子设备和电动交通中。富锂层状结构氧化物以高达300 m Ah·g^-1的可逆容量成为能量密度350 Wh·kg^-1及以上动力锂离子电池的重要候选正极材料。但是,欲使这类材料获得实际应用,就必须解决循环过程中结构衰退带来的一系列问题。本文重点介绍近几年来笔者所领导的研究组通过元素筛选实现材料的表面和体相掺杂,通过全新的结构设计稳定材料结构和性能方面的努力。同时,为使读者对国内外重要研究组在相关方面的研究进展也有所了解,我们也将从元素替代、结构一体化表面修饰(包括多层表面修饰和浓度梯度材料)、表面包覆和表面掺杂等方面介绍他们的重要研究成果。最后,将对该类材料的未来发展方向作出展望并给出我们的一些思考。
基金financially supported by the National Basic Research Program of China(Nos.2022YFA1603701,2024YFC2310502,and 2024YFC2310503)the National Natural Science Foundation of China(Nos.22422403,82341044,and 22027810)+1 种基金the New Cornerstone Science Foundation(No.NCI202318)the Basic Science Center Project of the National Natural Science Foundation of China(No.22388101).
文摘Drug-resistant bacteria,using their dense cell membranes as strong barrier,significantly reduce the efficacy of conventional antibacterial treatments.Phototriggered 2D catalytic nanomaterials have emerged as promising candidates against drug-resistant bacteria by inducing membrane mechanical damage and generating reactive oxygen species(ROS).However,the practical antibacterial efficacy of typical 2D graphitic carbon nitride(g-C_(3)N_(4))is severely limited due to the low ROS production.Herein,we report an interfacial band-engineered lamellar heterojunctions(MnCN LHJs)through in situ Mn_(2)O_(3)growth on g-C_(3)N_(4).The charges generated in g-C_(3)N_(4)are stabilized by Mn_(2)O_(3),minimizing electron-hole recombination and boosting ROS production.Meanwhile,the photocatalytic effect of MnCN LHJs works synergistically with photothermal effects of Mn_(2)O_(3)to induce a robust“melee attack”against drug-resistant bacteria.High-resolution synchrotron radiation X-ray tomography directly visualized that MnCN LHJs possessed bacterial trapping capabilities,revealing their ability to induce mechanical damage to bacteria membrane for the first time.Additionally,MnCN LHJs can deplete endogenous glutathione,thereby enhancing ROS generation and weakening the bacterial antioxidant defense system.These combined effects achieve a remarkable bactericidal rate exceeding 98% against methicillin-resistant Staphylococcus aureus(MRSA).Notably,MnCN LHJs demonstrate prolonged retention at wound sites,helping to reduce inflammation and promote angiogenesis in infected wounds.This work not only advances interfacial band engineering approach to enhance the photocatalytic performance of g-C_(3)N_(4)but also underscores the significance of nanomaterial-bacteria interaction in design of next-generation antibacterial materials.
基金financially supported by the National Natural Science Foundation of China(NSFC No.22075316,U23A20577,22005334,and 52172257)the Natural Science Foundation of Beijing(Grant No.Z200013).
文摘The continuous lithium consumption during cycling severely reduces the energy density of the lithium battery,and thus,lithium compensation is essential.Herein,Li_(x)C_(6)O_(6)(x=2,4)was proposed as an air-stable high-efficiency sacrificial additive in the cathode to compensate for the lost lithium ions in solid-state lithium batteries.Below a delithiation(oxidation)potential as low as 3.8 V,Li_(2)C_(6)O_(6) can release most of its Li^(+)ions(294.8 mAh g^(−1) in theory).Similarly,Li_(4)C_(6)O_(6) is also characteristic of low oxidation potential and high delithiation capacity(547.8 mAh g^(−1) in theory).The feasibility of using Li_(x)C_(6)O_(6) as the self-sacrificial additive in the cathode was verified with the marked increase of the initial charge capacity of the Li||LiFePO_(4)(half)cells and the initial discharge capacity of Cu||LiFePO_(4)(full)cells,and the improved electrolyte/cathode interface stability and interface contact,in the solid-state poly(ethylene oxide)-lithium bis(trifluoromethane)sulfonimide(PEO-LiTFSI)electrolyte.In addition,the structure and delithiation of Li_(x)C_(6)O_(6) and the impacts of its decomposition product on the PEO-LiTFSI solid electrolyte were also evaluated on the basis of the comprehensive physical characterizations and the density functional theory(DFT)calculations.These findings open a new avenue for elevating the energy density and/or elongate the lifespan of the solid-state secondary batteries.
