In general,acid aggregates are not used in combination with asphalt concrete because of their poor compatibility with the asphalt binder,which typically results in a scarce water stability of the concrete.In the prese...In general,acid aggregates are not used in combination with asphalt concrete because of their poor compatibility with the asphalt binder,which typically results in a scarce water stability of the concrete.In the present study,the feasibility of a new approach based on the combination of acid granite fine aggregate with alkaline limestone coarse aggregate and Portland cement filler has been assessed.The mineral and chemical compositions of these three materials have first been analyzed and compared.Then,the effect of different amounts of Portland cement(0%,25%,50%,75%and 100%of the total filler by weight)on the mechanical performance and water stability of the asphalt concrete has been considered.Asphalt concrete has been designed by using the Marshall method,and the mechanical performance indexes of this material,including the Marshall stability and indirect tensile strength(ITS),have been measured together with the related water stability indexes(namely the Marshall stability(RMS)and tensile strength ratio(TSR)).The results indicate that the alkaline limestone coarse aggregate and Portland cement filler can balance the drawback caused by the acid granite fine aggregate.The asphalt concrete has good mechanical performances and water stability when the amount of common limestone powder filler replaced by cement is not less than 75%.展开更多
Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion condu...Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion conductance and poor mechanical and thermal properties.Herein,poly(m-phenylene isophthalamide)(PMIA)is employed as a multifunctional additive to improve the overall properties of the PEO-based electrolytes.The hydrogen-bond interactions between PMIA and PEO/TFSI-can effectively prevent the PEO crystallization and meanwhile facilitate the LiTFSI dissociation,and thus greatly improve the ionic conductivity(two times that of the pristine electrolyte at room temperature).With the incorporation of the high-strength PMIA with tough amide-benzene backbones,the PMIA/PEO-LiTFSI composite polymer electrolyte(CPE)membranes also show much higher mechanical strength(2.96 MPa),thermostability(4190℃)and interfacial stability against Li dendrites(468 h at 0.10 mA cm-2)than the pristine electrolyte(0.32 MPa,364℃and short circuit after 246 h).Furthermore,the CPE-based LiFePO4/Li cells exhibit superior cycling stability(137 mAh g^-1 with 93%retention after 100 cycles at 0.5 C)and rate performance(123 mAh g^-1 at 1.0 C).This work provides a novel and effective CPE structure design strategy to achieve comprehensively-upgraded electrolytes for promising solid-state battery applications.展开更多
Li-rich layered oxide cathodes have received considerable attention because of the high operating potential and specific capacity. However, the structural instability and parasitic reactions at high potential cause se...Li-rich layered oxide cathodes have received considerable attention because of the high operating potential and specific capacity. However, the structural instability and parasitic reactions at high potential cause severe degradation of the electrochemical performance. In our studies, the cycling stability of Li_(1.14)Ni_(0.133)Co_(0.133)Mn_(0.544)O_(2) cathode is improved with LiPO_(2)F_(2) electrolyte additive. After 500 cycles, the capacity retention is increased from 53.6% to 85% at 3 C by LiPO_(2)F_(2) modification. This performance is mainly attributed to the enhanced interfacial stability of the Li-rich cathode. Based on systematic characterization, LiPO_(2)F_(2) additive was found to promote a stable interface film on the cathode surface during the cycling and mitigates the interfacial side reactions. This study provides new insights for improving high-potential Li-rich layered oxide batteries.展开更多
Bronze phase TiO_(2)[TiO_(2)(B)]has great research potential for sodium storage since it has a higher theoretical capacity and ion mobility compared with other phases of TiO_(2).In this case,preparing porous TiO_(2)(B...Bronze phase TiO_(2)[TiO_(2)(B)]has great research potential for sodium storage since it has a higher theoretical capacity and ion mobility compared with other phases of TiO_(2).In this case,preparing porous TiO_(2)(B)nanosheets,which can provide abundant sodium insertion channels,is the most effective way to improve transport kinetics.Here,we use the strong one-dimensional TiO_(2)nanowires as the matrix for stringing these nanosheets together through a simple solvothermal method to build a bunchy hierarchical structure[TiO_(2)(B)-BH],which has fast pseudocapacitance behavior,high structural stability,and effective ion/electron transport.With the superiorities of this structure design,TiO_(2)(B)-BH has a higher capacity(131 vs.70 mAh g^(−1)[TiO_(2)-NWs]at 0.5 C).And it is worth mentioning that the reversible capacity of up to 500 cycles can still be maintained at 85 mAh g^(−1)at a high rate of 10 C.Meanwhile,we also further analyzed the sodium storage mechanism through the ex-situ X-ray powder diffraction test,which proved the high structural stability of TiO_(2)(B)-BH in the process of sodiumization/de-sodiumization.This strategy of uniformly integrating nanosheets into a matrix can also be extended to preparing electrode material structures of other energy devices.展开更多
Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In ...Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In this work, the perovskite configuration of MAPbX(MA = CH_3 NH_3,X = I_3, Br_3, or I_2Br) integrated with stable and low-cost Cu:Ni Oxhole-transporting material, ZnO electron-transporting material, and Al counter electrode was modeled as a planar PSC and studied theoretically. A solar cell simulation program(wx AMPS), which served as an update of the popular solar cell simulation tool(AMPS: Analysis of Microelectronic and Photonic Structures), was used. The study yielded a detailed understanding of the role of each component in the solar celland its effect on the photovoltaic parameters as a whole. The bandgap of active materials and operating temperature of the modeled solar cell were shown to influence the solar cell performance in a significant way. Further, the simulation results reveal a strong dependence of photovoltaic parameters on the thickness and defect density of the light-absorbing layers. Under moderate simulation conditions, the MAPb Br_3 and MAPbI _2 Br cells recorded the highest PCEs of 20.58 and 19.08%, respectively, while MAPbI_3 cell gave a value of 16.14%.展开更多
Polyethylene oxide(PEO)-based electrolytes are considered as one of the most promising solid-state electrolytes for next-generation lithium batteries with high safety and energy density;however,the drawbacks such as i...Polyethylene oxide(PEO)-based electrolytes are considered as one of the most promising solid-state electrolytes for next-generation lithium batteries with high safety and energy density;however,the drawbacks such as insufficient ion conductance,mechanical strength and electrochemical stability hinder their applications in metallic lithium batteries.To enhance their overall properties,flexible and thin composite polymer electrolyte(CPE)membranes with 3D continuous aramid nanofiber(ANF)–Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4))_(3)(LATP)nanoparticle hybrid frameworks are facilely prepared by filling PEO–Li TFSI in the 3D nanohybrid scaffolds via a solution infusion way.The construction of the 3D continuous nanohybrid networks can effectively inhibit the PEO crystallization,facilitate the lithium salt dissociation and meanwhile increase the fast-ion transport in the continuous LATP electrolyte phase,and thus greatly improving the ionic conductivity(~3 times that of the pristine one).With the integration of the 3D continuity and flexibility of the 3D ANF networks and the thermostability of the LATP phase,the CPE membranes also show a wider electrochemical window(~5.0 V vs.4.3 V),higher tensile strength(~4–10times that of the pristine one)and thermostability,and better lithium dendrite resistance capability.Furthermore,the CPE-based Li FePO_(4)/Li cells exhibit superior cycling stability(133 m Ah/g after 100 cycles at 0.3 C)and rate performance(100 m Ah/g at 1 C)than the pristine electrolyte-based cell(79 and 29m Ah/g,respectively).This work offers an important CPE design criteria to achieve comprehensivelyupgraded solid-state electrolytes for safe and high-energy metal battery applications.展开更多
Boosting the interfacial stability between electrolyte and Li-rich cathode material at high operating voltage is vital important to enhance the cycling stability of Li-rich cathode materials for high-performance Li-io...Boosting the interfacial stability between electrolyte and Li-rich cathode material at high operating voltage is vital important to enhance the cycling stability of Li-rich cathode materials for high-performance Li-ion batteries.In this work,vinyltrimethylsilane as a new type of organic silicon electrolyte additive is studied to address the interfacial instability of Li-rich cathode material at high operating voltage.The cells using vinyltrimethylsilane additive shows the high capacity retention of 73.9%after 300 cycles at 1 C,whereas the cells without this kind of additive only have the capacity retention of 58.9%.The improvement of stability is mainly attributed to the additive helping to form a more stable surface film for Li-rich cathode material,thus avoiding direct contact between the electrolyte and the cathode material,slowing down the dissolution of metal ions and the decomposition of the electrolyte under high operating voltage.Our findings in this work shed some light on the design of stable cycling performance of Li-rich cathode toward advanced Li-ion batteries.展开更多
Solid polymer electrolytes(SPEs)possess comprehensive advantages such as high flexibility,low interfacial resistance with the electrodes,excellent film-forming ability,and low price,however,their applications in solid...Solid polymer electrolytes(SPEs)possess comprehensive advantages such as high flexibility,low interfacial resistance with the electrodes,excellent film-forming ability,and low price,however,their applications in solid-state batteries are mainly hindered by the insufficient ionic conductivity especially below the melting temperatures,etc.To improve the ion conduction capability and other properties,a variety of modification strategies have been exploited.In this review article,we scrutinize the structure characteristics and the ion transfer behaviors of the SPEs(and their composites)and then disclose the ion conduction mechanisms.The ion transport involves the ion hopping and the polymer segmental motion,and the improvement in the ionic conductivity is mainly attributed to the increase of the concentration and mobility of the charge carriers and the construction of fast-ion pathways.Furthermore,the recent advances on the modification strategies of the SPEs to enhance the ion conduction from copolymer structure design to lithium salt exploitation,additive engineering,and electrolyte micromorphology adjustion are summarized.This article intends to give a comprehensive,systemic,and profound understanding of the ion conduction and enhancement mechanisms of the SPEs for their viable applications in solid-state batteries with high safety and energy density.展开更多
High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection.The combination of highly conductive MXene and metal oxide materials is a promising stra...High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection.The combination of highly conductive MXene and metal oxide materials is a promising strategy to further improve the sensing performances.In this study,the hollow SnO_(2)nanospheres and few-layer MXene are assembled rationally via facile electrostatic synthesis processes,then the SnO_(2)/Ti_(3)C_(2)T_(x)nanocomposites were obtained.Compared with that based on either pure SnO_(2)nanoparticles or hollow nanospheres of SnO_(2),the SnO_(2)/Ti_(3)C_(2)T_(x)composite-based sensor exhibits much better sensing performances such as higher response(36.979),faster response time(5 s),and much improved selectivity as well as stability(15 days)to 100ppm C2H5OH at low working temperature(200°C).The improved sensing performances are mainly attributed to the large specific surface area and significantly increased oxygen vacancy concentration,which provides a large number of active sites for gas adsorption and surface catalytic reaction.In addition,the heterostructure interfaces between SnO_(2)hollow spheres and MXene layers are beneficial to gas sensing behaviors due to the synergistic effect.展开更多
Highly safe and efficient rechargeable lithium batteries have become an indispensable component of the intelligent society powering smart electronics and electric vehicles.This review summarizes the formation principl...Highly safe and efficient rechargeable lithium batteries have become an indispensable component of the intelligent society powering smart electronics and electric vehicles.This review summarizes the formation principle,chemical compositions,and theoretical models of the solid electrolyte interphase(SEI)on the anode in the lithium battery,involving the functions and influences of the electroactive materials.The discrepancies of the SEI on different kinds of anode materials,as well as the choice and design of the electrolytes are detailedly clarified.Furthermore,the design strategies to obtain a stable and efficient SEI are outlined and discussed.Last but not least,the challenges and perspectives of artificial SEI technology are briefly proposed for the development of high-efficiency batteries in practice.展开更多
聚合物电解质在锂金属电池中的应用受限于锂枝晶生长、电化学不稳定性及较低的离子电导率.为解决这些问题,本文通过向三维多孔芳纶纳米纤维(ANF)中填充聚环氧乙烷(PEO)-双三氟甲基磺酰亚胺锂(LiTFSI)电解质,制备了基于三维芳纶纳米纤维...聚合物电解质在锂金属电池中的应用受限于锂枝晶生长、电化学不稳定性及较低的离子电导率.为解决这些问题,本文通过向三维多孔芳纶纳米纤维(ANF)中填充聚环氧乙烷(PEO)-双三氟甲基磺酰亚胺锂(LiTFSI)电解质,制备了基于三维芳纶纳米纤维网络骨架的柔性ANF/PEO-LiTFSI复合电解质薄膜.由于其独特的构造及离子在三维ANF/PEO-LiTFSI界面中的连续输运,该复合电解质膜具有比PEO-LiTFSI电解质膜更高的力学强度(10.0 MPa)、热稳定性、电化学稳定性(60℃下达4.6 V)和离子电导率,以及较强的抑制锂枝晶能力.基于该复合电解质的固态LiFePO4/Li电池表现出优异的循环性能(在0.4 C下充放电百次后的容量达130 mA h g-1、保持率为93%).该研究提供了一种基于三维骨架设计和制备高性能电解质的有效方法,有望应用于固态锂金属电池.展开更多
基金supported by the Science and Technology Planning Project of Zhejiang Provincial Department of Transportation(2021012)Zhejiang Provincial Natural Science Foundation of China under Grant(No.LGG21E080002).
文摘In general,acid aggregates are not used in combination with asphalt concrete because of their poor compatibility with the asphalt binder,which typically results in a scarce water stability of the concrete.In the present study,the feasibility of a new approach based on the combination of acid granite fine aggregate with alkaline limestone coarse aggregate and Portland cement filler has been assessed.The mineral and chemical compositions of these three materials have first been analyzed and compared.Then,the effect of different amounts of Portland cement(0%,25%,50%,75%and 100%of the total filler by weight)on the mechanical performance and water stability of the asphalt concrete has been considered.Asphalt concrete has been designed by using the Marshall method,and the mechanical performance indexes of this material,including the Marshall stability and indirect tensile strength(ITS),have been measured together with the related water stability indexes(namely the Marshall stability(RMS)and tensile strength ratio(TSR)).The results indicate that the alkaline limestone coarse aggregate and Portland cement filler can balance the drawback caused by the acid granite fine aggregate.The asphalt concrete has good mechanical performances and water stability when the amount of common limestone powder filler replaced by cement is not less than 75%.
基金supported partially by Natural Science Foundation of Beijing Municipality(L172036)Joint Funds of the Equipment Pre-Research and Ministry of Education(6141A020225)+3 种基金Par-Eu Scholars Program,Science and Technology Beijing 100 Leading Talent Training ProjectChina Postdoctoral Science Foundation(2018M631419)Fundamental Research Funds for Central Universities(2017ZZD02,2019QN001)NCEPU“Double First-Class”Graduate Talent Cultivation Program。
文摘Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion conductance and poor mechanical and thermal properties.Herein,poly(m-phenylene isophthalamide)(PMIA)is employed as a multifunctional additive to improve the overall properties of the PEO-based electrolytes.The hydrogen-bond interactions between PMIA and PEO/TFSI-can effectively prevent the PEO crystallization and meanwhile facilitate the LiTFSI dissociation,and thus greatly improve the ionic conductivity(two times that of the pristine electrolyte at room temperature).With the incorporation of the high-strength PMIA with tough amide-benzene backbones,the PMIA/PEO-LiTFSI composite polymer electrolyte(CPE)membranes also show much higher mechanical strength(2.96 MPa),thermostability(4190℃)and interfacial stability against Li dendrites(468 h at 0.10 mA cm-2)than the pristine electrolyte(0.32 MPa,364℃and short circuit after 246 h).Furthermore,the CPE-based LiFePO4/Li cells exhibit superior cycling stability(137 mAh g^-1 with 93%retention after 100 cycles at 0.5 C)and rate performance(123 mAh g^-1 at 1.0 C).This work provides a novel and effective CPE structure design strategy to achieve comprehensively-upgraded electrolytes for promising solid-state battery applications.
基金supported partially by the Natural Science Foundation of Beijing Municipality (L172036)the Joint Funds of the Equipment Pre-Research and Ministry of Education (6141A020225)+2 种基金the National Natural Science Foundation of China (Grants Nos. 52072323 and 51872098)the Science and Technology Beijing 100 Leading Talent Training Projectthe NCEPU ‘‘Double First-Class” Program. We thank Dr. Rui Liu for suggestions on the crystal structure analysis。
文摘Li-rich layered oxide cathodes have received considerable attention because of the high operating potential and specific capacity. However, the structural instability and parasitic reactions at high potential cause severe degradation of the electrochemical performance. In our studies, the cycling stability of Li_(1.14)Ni_(0.133)Co_(0.133)Mn_(0.544)O_(2) cathode is improved with LiPO_(2)F_(2) electrolyte additive. After 500 cycles, the capacity retention is increased from 53.6% to 85% at 3 C by LiPO_(2)F_(2) modification. This performance is mainly attributed to the enhanced interfacial stability of the Li-rich cathode. Based on systematic characterization, LiPO_(2)F_(2) additive was found to promote a stable interface film on the cathode surface during the cycling and mitigates the interfacial side reactions. This study provides new insights for improving high-potential Li-rich layered oxide batteries.
基金the Natural Science Foundation of Beijing Municipality(L172036)Joint Funds of the Equipment Pre-Research and Ministry of Education(6141A020225)+1 种基金Par-Eu Scholars Program,Science and Technology Beijing 100 Leading Talent Training Project,the Fundamental Research Funds for the Central Universities(2020FR002,2020MS023,2020MS028,2021MS028)the NCEPU"Double First-Class"Program,the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(LAPS21004).
文摘Bronze phase TiO_(2)[TiO_(2)(B)]has great research potential for sodium storage since it has a higher theoretical capacity and ion mobility compared with other phases of TiO_(2).In this case,preparing porous TiO_(2)(B)nanosheets,which can provide abundant sodium insertion channels,is the most effective way to improve transport kinetics.Here,we use the strong one-dimensional TiO_(2)nanowires as the matrix for stringing these nanosheets together through a simple solvothermal method to build a bunchy hierarchical structure[TiO_(2)(B)-BH],which has fast pseudocapacitance behavior,high structural stability,and effective ion/electron transport.With the superiorities of this structure design,TiO_(2)(B)-BH has a higher capacity(131 vs.70 mAh g^(−1)[TiO_(2)-NWs]at 0.5 C).And it is worth mentioning that the reversible capacity of up to 500 cycles can still be maintained at 85 mAh g^(−1)at a high rate of 10 C.Meanwhile,we also further analyzed the sodium storage mechanism through the ex-situ X-ray powder diffraction test,which proved the high structural stability of TiO_(2)(B)-BH in the process of sodiumization/de-sodiumization.This strategy of uniformly integrating nanosheets into a matrix can also be extended to preparing electrode material structures of other energy devices.
基金supported partially by National Natural Science Foundation of China (Grant Nos. 51772096, 51372082, 51402106, and 11504107)Beijing Natural Science Foundation (17L20075)+4 种基金Joint Funds of the Equipment Pre-Research and Ministry of Education (6141A020225)National High-tech R&D Program of China (863 Program, No. 2015AA034601)Par-Eu Scholars ProgramBeijing Municipal Science and Technology Project (Z161100002616039)the Fundamental Research Funds for the Central Universities (2016JQ01, 2017ZZD02)
文摘Although perovskite solar cells with power conversion efficiencies(PCEs) more than 22% have been realized with expensive organic charge-transporting materials, their stability and high cost remain to be addressed. In this work, the perovskite configuration of MAPbX(MA = CH_3 NH_3,X = I_3, Br_3, or I_2Br) integrated with stable and low-cost Cu:Ni Oxhole-transporting material, ZnO electron-transporting material, and Al counter electrode was modeled as a planar PSC and studied theoretically. A solar cell simulation program(wx AMPS), which served as an update of the popular solar cell simulation tool(AMPS: Analysis of Microelectronic and Photonic Structures), was used. The study yielded a detailed understanding of the role of each component in the solar celland its effect on the photovoltaic parameters as a whole. The bandgap of active materials and operating temperature of the modeled solar cell were shown to influence the solar cell performance in a significant way. Further, the simulation results reveal a strong dependence of photovoltaic parameters on the thickness and defect density of the light-absorbing layers. Under moderate simulation conditions, the MAPb Br_3 and MAPbI _2 Br cells recorded the highest PCEs of 20.58 and 19.08%, respectively, while MAPbI_3 cell gave a value of 16.14%.
基金supported partially by the project of State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(LAPS21004)the National Natural Science Foundation of China(51972110,52102245,52072121)+5 种基金the Beijing Science and Technology Project(Z211100004621010)the Beijing Natural Science Foundation(2222076,2222077)the Huaneng Group Headquarters Science and Technology Project(HNKJ20-H88)the Hebei Natural Science Foundation(E2022502022)the Fundamental Research Funds for the Central Universities(2021MS028,2020MS023,2020MS028)the NCEPU“Double First-Class”Program。
文摘Polyethylene oxide(PEO)-based electrolytes are considered as one of the most promising solid-state electrolytes for next-generation lithium batteries with high safety and energy density;however,the drawbacks such as insufficient ion conductance,mechanical strength and electrochemical stability hinder their applications in metallic lithium batteries.To enhance their overall properties,flexible and thin composite polymer electrolyte(CPE)membranes with 3D continuous aramid nanofiber(ANF)–Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4))_(3)(LATP)nanoparticle hybrid frameworks are facilely prepared by filling PEO–Li TFSI in the 3D nanohybrid scaffolds via a solution infusion way.The construction of the 3D continuous nanohybrid networks can effectively inhibit the PEO crystallization,facilitate the lithium salt dissociation and meanwhile increase the fast-ion transport in the continuous LATP electrolyte phase,and thus greatly improving the ionic conductivity(~3 times that of the pristine one).With the integration of the 3D continuity and flexibility of the 3D ANF networks and the thermostability of the LATP phase,the CPE membranes also show a wider electrochemical window(~5.0 V vs.4.3 V),higher tensile strength(~4–10times that of the pristine one)and thermostability,and better lithium dendrite resistance capability.Furthermore,the CPE-based Li FePO_(4)/Li cells exhibit superior cycling stability(133 m Ah/g after 100 cycles at 0.3 C)and rate performance(100 m Ah/g at 1 C)than the pristine electrolyte-based cell(79 and 29m Ah/g,respectively).This work offers an important CPE design criteria to achieve comprehensivelyupgraded solid-state electrolytes for safe and high-energy metal battery applications.
基金supported partially by State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Nos.LAPS_(2)1004,LAPS_(2)02114)National Natural Science Foundation of China(Nos.52272200,51972110,52102245 and 52072121)+6 种基金Beijing Science and Technology Project(No.Z211100004621010)Beijing Natural Science Foundation(Nos.2222076,2222077)Hebei Natural Science Foundation(No.E2022502022)Huaneng Group Headquarters Science and Technology Project(No.HNKJ20-H88)2022 Strategic Research Key Project of Science and Technology Commission of the Ministry of Education,China Postdoctoral Science Foundation(No.2022M721129)the Fundamental Research Funds for the Central Universities(Nos.2022MS030,2021MS028,2020MS023,2020MS028)the NCEPU"Double First-Class"Program and the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(No.LAPS22005).
文摘Boosting the interfacial stability between electrolyte and Li-rich cathode material at high operating voltage is vital important to enhance the cycling stability of Li-rich cathode materials for high-performance Li-ion batteries.In this work,vinyltrimethylsilane as a new type of organic silicon electrolyte additive is studied to address the interfacial instability of Li-rich cathode material at high operating voltage.The cells using vinyltrimethylsilane additive shows the high capacity retention of 73.9%after 300 cycles at 1 C,whereas the cells without this kind of additive only have the capacity retention of 58.9%.The improvement of stability is mainly attributed to the additive helping to form a more stable surface film for Li-rich cathode material,thus avoiding direct contact between the electrolyte and the cathode material,slowing down the dissolution of metal ions and the decomposition of the electrolyte under high operating voltage.Our findings in this work shed some light on the design of stable cycling performance of Li-rich cathode toward advanced Li-ion batteries.
基金This work was supported partially by project of the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Nos.LAPS21004 and LAPS202114)the Hebei Natural Science Foundation(No.E2022502022)+5 种基金the National Natural Science Foundation of China(Nos.52272200,51972110,52102245,and 52072121)the Beijing Science and Technology Project(No.Z211100004621010)the Beijing Natural Science Foundation(Nos.2222076 and 2222077)the Huaneng Group Headquarters Science and Technology Project(No.HNKJ20-H88)the 2022 Strategic Research Key Project of Science and Technology Commission of the Ministry of Education,the China Postdoctoral Science Foundation(No.2022M721129)the Fundamental Research Funds for the Central Universities(Nos.2022MS030,2021MS028,2020MS023,and 2020MS028),and the NCEPU“Double First-Class”Program.
文摘Solid polymer electrolytes(SPEs)possess comprehensive advantages such as high flexibility,low interfacial resistance with the electrodes,excellent film-forming ability,and low price,however,their applications in solid-state batteries are mainly hindered by the insufficient ionic conductivity especially below the melting temperatures,etc.To improve the ion conduction capability and other properties,a variety of modification strategies have been exploited.In this review article,we scrutinize the structure characteristics and the ion transfer behaviors of the SPEs(and their composites)and then disclose the ion conduction mechanisms.The ion transport involves the ion hopping and the polymer segmental motion,and the improvement in the ionic conductivity is mainly attributed to the increase of the concentration and mobility of the charge carriers and the construction of fast-ion pathways.Furthermore,the recent advances on the modification strategies of the SPEs to enhance the ion conduction from copolymer structure design to lithium salt exploitation,additive engineering,and electrolyte micromorphology adjustion are summarized.This article intends to give a comprehensive,systemic,and profound understanding of the ion conduction and enhancement mechanisms of the SPEs for their viable applications in solid-state batteries with high safety and energy density.
基金This work is supported partially by the project of the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Nos.LAPS21004,LAPS202114)National Natural Science Foundation of China(Nos.52272200,51972110,52102245 and 52072121)+6 种基金Beijing Science and Technology Project(No.Z211100004621010)Beijing Natural Science Foundation(Nos.2222076,2222077)Hebei Natural Science Foundation(No.E2022502022)Huaneng Group Headquarters Science and Technology Project(No.HNKJ20-H88)2022 Strategic Research Key Project of Science and Technology Commission of the Ministry of Education,China Postdoctoral Science Foundation(No.2022M721129)the Fundamental Research Funds for the Central Universities(Nos.2022MS030,2021MS028,2020MS023,2020MS028)the NCEPU“Double First-Class”Program.This research was also supported by Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea(No.2021H1D3A2A01100019).
文摘High-performance and low-cost gas sensors are highly desirable and involved in industrial production and environmental detection.The combination of highly conductive MXene and metal oxide materials is a promising strategy to further improve the sensing performances.In this study,the hollow SnO_(2)nanospheres and few-layer MXene are assembled rationally via facile electrostatic synthesis processes,then the SnO_(2)/Ti_(3)C_(2)T_(x)nanocomposites were obtained.Compared with that based on either pure SnO_(2)nanoparticles or hollow nanospheres of SnO_(2),the SnO_(2)/Ti_(3)C_(2)T_(x)composite-based sensor exhibits much better sensing performances such as higher response(36.979),faster response time(5 s),and much improved selectivity as well as stability(15 days)to 100ppm C2H5OH at low working temperature(200°C).The improved sensing performances are mainly attributed to the large specific surface area and significantly increased oxygen vacancy concentration,which provides a large number of active sites for gas adsorption and surface catalytic reaction.In addition,the heterostructure interfaces between SnO_(2)hollow spheres and MXene layers are beneficial to gas sensing behaviors due to the synergistic effect.
基金supported partially by the project of the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(Nos.LAPS21004 and LAPS202114)National Natural Science Foundation of China(Nos.52272200,51972110,52102245,and 52072121)+6 种基金Beijing Science and Technology Project(No.Z211100004621010)Beijing Natural Science Foundation(Nos.2222076 and 2222077)Hebei Natural Science Foundation(No.E2022502022)Huaneng Group Headquarters Science and Technology Project((No.HNKJ20-H88)2022 Strategic Research Key Project of Science and Technology Commission of the Ministry of Education,China Postdoctoral Science Foundation(No.2022M721129)the Fundamental Research Funds for the Central Universities(Nos.2022MS030,2021MS028,2020MS023,and 2020MS028)the NCEPU“Double First-Class”Program.
文摘Highly safe and efficient rechargeable lithium batteries have become an indispensable component of the intelligent society powering smart electronics and electric vehicles.This review summarizes the formation principle,chemical compositions,and theoretical models of the solid electrolyte interphase(SEI)on the anode in the lithium battery,involving the functions and influences of the electroactive materials.The discrepancies of the SEI on different kinds of anode materials,as well as the choice and design of the electrolytes are detailedly clarified.Furthermore,the design strategies to obtain a stable and efficient SEI are outlined and discussed.Last but not least,the challenges and perspectives of artificial SEI technology are briefly proposed for the development of high-efficiency batteries in practice.
基金supported partially by Beijing Natural Science Foundation(L172036)Joint Funds of the Equipment Pre-Research and Ministry of Education(6141A020225)+2 种基金Par-Eu Scholars Program,Science and Technology Beijing 100 Leading Talent Training Project,Beijing Municipal Science and Technology Project(Z161100002616039)China Postdoctoral Science Foundation(2018M631419)the Fundamental Research Funds for the Central Universities(2017ZZD02 and 2019QN001).
文摘聚合物电解质在锂金属电池中的应用受限于锂枝晶生长、电化学不稳定性及较低的离子电导率.为解决这些问题,本文通过向三维多孔芳纶纳米纤维(ANF)中填充聚环氧乙烷(PEO)-双三氟甲基磺酰亚胺锂(LiTFSI)电解质,制备了基于三维芳纶纳米纤维网络骨架的柔性ANF/PEO-LiTFSI复合电解质薄膜.由于其独特的构造及离子在三维ANF/PEO-LiTFSI界面中的连续输运,该复合电解质膜具有比PEO-LiTFSI电解质膜更高的力学强度(10.0 MPa)、热稳定性、电化学稳定性(60℃下达4.6 V)和离子电导率,以及较强的抑制锂枝晶能力.基于该复合电解质的固态LiFePO4/Li电池表现出优异的循环性能(在0.4 C下充放电百次后的容量达130 mA h g-1、保持率为93%).该研究提供了一种基于三维骨架设计和制备高性能电解质的有效方法,有望应用于固态锂金属电池.