For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors,potassium ions are pre-inserted into MnO2 tunnel structure,the as-prepared K1.04Mn8 O16 materials consist of nanoparticles and nano...For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors,potassium ions are pre-inserted into MnO2 tunnel structure,the as-prepared K1.04Mn8 O16 materials consist of nanoparticles and nanorods were prepared by facile high-temperature solid-state reaction.The as-prepared materials were well studied and they show outstanding electrochemical behavior.We assembled hybrid supercapacitors with commercial activated carbon(YEC-8 A)as anode and K1.04Mn8 O16 as cathode.It shows high energy and power densities.Li-ion capacitors reach a high energy density of 127.61 Wh kg-1 at the power density of 99.86 W kg-1 and Na-ion capacitor obtains 170.96 Wh kg-1 at 133.79 W kg-1.In addition,the hybrid supercapacitors demonstrate excellent cycling performance which maintain 97%capacitance retention for Li-ion capacitor and 85%for Na-ion capacitor after 10,000 cycles.展开更多
Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to t...Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage range.Herein,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation stability.We originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°C.The study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.展开更多
Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in uns...Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and stoichiometry.Herein,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation kinetics.The well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation process.After coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full batteries.The enhancement mechanism has also been clarified.These findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.展开更多
Manufacturing process,diffusion co-efficient and areal capacity are the three main criteria for regulating thick electrodes for lithium-ion batteries(LIBs).However,simultaneously regulating these criteria for LIBs is ...Manufacturing process,diffusion co-efficient and areal capacity are the three main criteria for regulating thick electrodes for lithium-ion batteries(LIBs).However,simultaneously regulating these criteria for LIBs is desirable but remains a significant challenge.In this work,niobium pentoxide(Nb_(2)O_(5))anode and lithium iron phosphate(LiFePO_(4))cathode materials were chosen as the model materials and demonstrate that these three parameters can be simultaneously modulated by incorporation of micro-carbon fibers(MCF)and carbon nanotubes(CNT)with both Nb_(2)O_(5) and LFP via vacuum filtration approach.Both as-prepared MNC-20 anode and MLC-20 cathode achieves high reversible areal capacity of≈5.4 m A h cm^(-2)@0.1 C and outstanding Li-ion diffusion coefficients of≈10~(-8)cm~2 s~(-1)in the half-cell configuration.The assembled MNC-20‖MLC-20 full cell LIB delivers maximum energy and power densities of244.04 W h kg^(-1)and 108.86 W kg^(-1),respectively.The excellent electrochemical properties of the asprepared thick electrodes can be attributed to the highly conductive,mechanical compactness and multidimensional mutual effects of the MCF,CNT and active materials that facilitates rapid Li-ion diffusion kinetics.Furthermore,electrochemical impedance spectroscopy(EIS),symmetric cells analysis,and insitu Raman techniques clearly validates the enhanced Li-ion diffusion kinetics in the present architecture.展开更多
This review highlights the importance of recovering valuable metals from spent Li-ion battery(LIB)cathodes through the resynthesis of cathode active materials(CAMs).The resynthesis process of CAMs,a promising recyclin...This review highlights the importance of recovering valuable metals from spent Li-ion battery(LIB)cathodes through the resynthesis of cathode active materials(CAMs).The resynthesis process of CAMs,a promising recycling method that directly produces CAM precursors from LIB leachate,is explored.This process encompasses six key steps,including pretreatment,leaching,purification,adjustment of metal concentrations,precursor synthesis,and sintering.The review also investigates the potential introduction of impurity elements during CAM resynthesis and provides tolerance levels for these impurities based on thorough reference analysis.Additionally,it addresses challenges related to the commercialization of the resynthesis process.Notably,this review represents the first comprehensive assessment of CAM resynthesis,including the systematic evaluation of 12 impurity elements(Fe,Li,Al,Cu,C,P,F,Na,Cl,S,Mg,and Zn).Overall,this comprehensive review is poised to support the commercial development of resynthesized CAMs by offering valuable guidelines for managing impurities and streamlining the purification process.展开更多
The electrochromic Li-ion batteries(ELIBs) combine the functions of electrochromism and energy storage,realizing the display of energy-storage levels by visual signals. However, the accompanying interfacial issues inc...The electrochromic Li-ion batteries(ELIBs) combine the functions of electrochromism and energy storage,realizing the display of energy-storage levels by visual signals. However, the accompanying interfacial issues including physical contact and(electro)chemical stability should be taken into account when the conventional liquid/gel electrolytes are replaced with solid-state counterparts. Herein, the in-situ liquid-solid transitional succinonitrile(SCN) plastic glues are constructed between electrodes and poly(ethylene oxide)(PEO) polymer electrolytes, enabling an interface-reinforced solid-state ELIB.Specifically, the liquid SCN precursor can adequately wet electrode/PEO interfaces at high temperature,while it returns back to solid state at room temperature, leading to seamless interfacial contact and smooth ionic transfer without changing the solid state of the device. Moreover, the SCN interlayer suppresses the direct contact of PEO with electrodes containing high-valence metal ions, evoking the improved interfacial stability by inhibiting the oxidation of PEO. Therefore, the resultant solid-state ELIB with configuration of LiMn_(2)O_(4)/SCN-PEO-SCN/WO_(3) delivers an initial discharge capacity of 111 m A h g^(-1) along with a capacity retention of 88.3% after 200 cycles at 30 ℃. Meanwhile, the electrochromic function is integrated into the device by distinguishing its energy-storage levels through distinct color changes. This work proposes a promising solid-state ELIB with greatly reinforced interfacial compatibility by introducing in-situ solidified plastic glues.展开更多
To achieve high-energy-density and safe lithium-metal batteries(LMBs),solid-state electrolytes(SSEs)that exhibit fast Li-ion conductivity and good stability against lithium metal are of great importance.This study pre...To achieve high-energy-density and safe lithium-metal batteries(LMBs),solid-state electrolytes(SSEs)that exhibit fast Li-ion conductivity and good stability against lithium metal are of great importance.This study presents a systematic exploration of selenide-based materials as potential SSE candidates.Initially,Li_(8)SeN_(2)and Li_(7)PSe_(6)were selected from 25 ternary selenides based on their ability to form stable interfaces with lithium metal.Subsequently,their favorable electronic insulation and mechanical properties were verified.Furthermore,extensive theoretical investigations were conducted to elucidate the fundamental mechanisms underlying Li-ion migration in Li_(8)SeN_(2),Li_(7)PSe_(6),and derived Li_(6)PSe_(5)X(X=Cl,Br,I).Notably,the highly favorable Li-ion conduction mechanism of vacancy diffusion was identified in Li6PSe5Cl and Li_(7)PSe_(6),which exhibited remarkably low activation energies of 0.21 and 0.23 eV,and conductivity values of 3.85×10^(-2)and 2.47×10^(-2)S cm^(-1)at 300 K,respectively.In contrast,Li-ion migration in Li_(8)SeN_(2)was found to occur via a substitution mechanism with a significant diffusion energy barrier,resulting in a high activation energy and low Li-ion conductivity of 0.54 eV and 3.6×10^(-6)S cm^(-1),respectively.Throughout this study,it was found that the ab initio molecular dynamics and nudged elastic band methods are complementary in revealing the Li-ion conduction mechanisms.Utilizing both methods proved to be efficient,as relying on only one of them would be insufficient.The discoveries made and methodology presented in this work lay a solid foundation and provide valuable insights for future research on SSEs for LMBs.展开更多
Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of LiNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formati...Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of LiNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formation energy of Li_(x)NiO_(2).Meanwhile,the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4,2/5,3/7,1/2,2/3,3/4,5/6,and 6/7 are predicted.To understand the capacity decay in the experiment during the charge/discharge cycles,deoxygenation and Li/Ni antisite defects are calculated,revealing that the chains of oxygen vacancies will be energetically preferrable.It can be inferred that in the absence of oxygen atom in high delithiate state,the diffusion of Ni atoms is facilitated and the formation of Li/Ni antisite is induced.展开更多
Two-dimensional(2D)metal-organic frameworks(MOFs)are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily a...Two-dimensional(2D)metal-organic frameworks(MOFs)are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily available active sites,and versatile,adaptable structures.These promising characteristics have positioned them as highly appealing alternatives for a wide range of applications in energy storage technologies,including lithium batteries.Nevertheless,the poor conductivity and limited stability of 2D MOFs have limited their real applications in electrochemical energy storage.These limitations have therefore warranted ongoing research to enhance the performance of 2D MOFs.Given the significance of 2D MOF-based materials as an emerging class of advanced materials,a multitude of strategy has been devised to address these challenges such as synthesizing 2D conductive MOFs and derivatives along with 2D MOF hybridization.One promising approach involves the use of 2D MOF derivatives,including transition metal oxides,which due to their abundant unsatu rated active metal sites and shorter diffusion paths,offer superior electrochemical performance.Additionally,by combining pristine 2D MOFs with other materials,hybrid 2D MOF materials can be created.These hybrids,with their enhanced stability and conductivity,can be directly utilized as active materials in lithium batteries.In the present review,we categorize 2D MOF-based materials into three distinct groups:pristine 2D MOFs,2D MOFderived materials,and 2D MOF hybrid materials.The synthesis methods for each group,along with their specific applications as electrode materials in lithium-ion batteries,are discussed in detail.This comprehensive review provides insights into the potential of 2D MOFs while highlighting the opportunities and challenges that are present in this evolving field.展开更多
One of the new methods for ensuring that the battery in a thermal energy storage system is kept at the proper temperature is the heat pipe-based ThermalManagement System(TMS).In this study,the improvement of cooling p...One of the new methods for ensuring that the battery in a thermal energy storage system is kept at the proper temperature is the heat pipe-based ThermalManagement System(TMS).In this study,the improvement of cooling performance of a heat pipe based TMS is examined through the variation of condenser section length of heat pipes in an array.The TMSs with an array of heat pipes with different condenser section lengths are considered.The system performances are evaluated using a validated numerical method.The results show that a heat pipebased TMS provides the best cooling performance when a wavy-like variation is employed and when the condenser section length of the last set of the heat pipe in the array is greater than that of the penultimate set.The maximum cell temperature and the maximum temperature difference within the cell of this TMS are decreased by 4.2 K and 1.1 K,respectively,when compared to the typical heat pipe based TMS with zero variation in its condenser section length.Conclusively,the strategy offers an improvement in the thermal uniformity for all the TMS cases.展开更多
该实验采用乙二胺四乙酸二钠(EDTA-2Na)-磷酸(2 g-5 m L)蒸馏体系对高粱、大曲、酒醅中的氰化物进行蒸馏提取,并结合全自动流动注射分析技术建立了高粱、大曲、酒醅中氰化物的快速测定方法。结果表明,氰化物在5~200μg/L范围内具有良好...该实验采用乙二胺四乙酸二钠(EDTA-2Na)-磷酸(2 g-5 m L)蒸馏体系对高粱、大曲、酒醅中的氰化物进行蒸馏提取,并结合全自动流动注射分析技术建立了高粱、大曲、酒醅中氰化物的快速测定方法。结果表明,氰化物在5~200μg/L范围内具有良好的线性关系(R2=0.999 6),检出限(LOD)为8.10μg/kg,定量限(LOQ)为25.00μg/kg;精密度、重复性、稳定性均良好,相对标准偏差(RSD)均<10%;样品的加标回收率为82.23%~97.64%。该检测技术前处理简便,检测效率较高,定量结果准确可靠,适用于大批量高粱、大曲、酒醅样品中氰化物的检测分析,对于提升白酒的质量安全监测能力具有重要的实际意义。展开更多
We propose a method for producing composite materials(hTNO@C_(60))comprising crystalline C_(60)particles and hollow-structu red TiNb_(2)O_(7)(hTNO)nanofibers via facile liquid-liquid interface precipitation followed b...We propose a method for producing composite materials(hTNO@C_(60))comprising crystalline C_(60)particles and hollow-structu red TiNb_(2)O_(7)(hTNO)nanofibers via facile liquid-liquid interface precipitation followed by low-temperature annealing.This allows the systematic design of crystalline C_(60)as an active material for Li-ion battery anodes.The hTNO@C_(60)composite demonstrates outstanding cyclic stability,retaining a capacity of 465 mA h g^(-1)after 1,000 cycles at 1 A g^(-1)It maintains a capacity of 98 mA h g^(-1)even after16,000 ultralong cycles at 8 A g^(-1)The enhancement in electrochemical properties is attributed to the successful growth and uniform doping of crystalline C_(60),resulting in improved electrical conductivity.The excellent electrochemical stability and properties of these composites make them promising anode materials.展开更多
A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage (CC- CV) charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the ...A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage (CC- CV) charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the beginning, and then the charging current begins to decrease before the battery voltage reaches its final value. After the battery voltage reaches its final value and remains constant,the charging current is further reduced. This approach prevents charging the battery with full current near its saturated voltage,which can cause heating. The novel design of the core of the charger IC realizes the proposed CC-CV charge mode. The chip was implemented in a CSMC 0.6μm CMOS mixed signal process. The experimental results verify the realization of the proposed CC- CV charge mode. The voltage of the battery after charging is 4. 1833V.展开更多
基金financially supported by the Fundamental Research Funds of Shangdong University(2016JC005,2017JC042,2017JC010)High-level Talents’Discipline Construction Fund of Shandong University(31370089963078)+1 种基金Technology Major Project(2017CXGC1010,2018JMRH0211,ZR2017MEM002)School research startup expenses of Harbin Institute of Technology(Shenzhen)(DD29100027)。
文摘For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors,potassium ions are pre-inserted into MnO2 tunnel structure,the as-prepared K1.04Mn8 O16 materials consist of nanoparticles and nanorods were prepared by facile high-temperature solid-state reaction.The as-prepared materials were well studied and they show outstanding electrochemical behavior.We assembled hybrid supercapacitors with commercial activated carbon(YEC-8 A)as anode and K1.04Mn8 O16 as cathode.It shows high energy and power densities.Li-ion capacitors reach a high energy density of 127.61 Wh kg-1 at the power density of 99.86 W kg-1 and Na-ion capacitor obtains 170.96 Wh kg-1 at 133.79 W kg-1.In addition,the hybrid supercapacitors demonstrate excellent cycling performance which maintain 97%capacitance retention for Li-ion capacitor and 85%for Na-ion capacitor after 10,000 cycles.
基金supported by the National Natural Science Foundation of China (No.92372123)the Natural Science Foundation of Guangdong Province (No.2022B1515020005)the Department of Science and Technology of Guangdong Province (No.2020B0101030005)
文摘Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage range.Herein,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation stability.We originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°C.The study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.
基金supported by the National Natural Science Foundation of China(21975074,91834301)the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities.
文摘Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and stoichiometry.Herein,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation kinetics.The well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation process.After coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full batteries.The enhancement mechanism has also been clarified.These findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.
基金supported by the Science and Technology Innovation Program of Hunan Province(2022WZ1012)the Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy(2020CB1007)the Natural Science Foundation of Guangzhou(202201020147)。
文摘Manufacturing process,diffusion co-efficient and areal capacity are the three main criteria for regulating thick electrodes for lithium-ion batteries(LIBs).However,simultaneously regulating these criteria for LIBs is desirable but remains a significant challenge.In this work,niobium pentoxide(Nb_(2)O_(5))anode and lithium iron phosphate(LiFePO_(4))cathode materials were chosen as the model materials and demonstrate that these three parameters can be simultaneously modulated by incorporation of micro-carbon fibers(MCF)and carbon nanotubes(CNT)with both Nb_(2)O_(5) and LFP via vacuum filtration approach.Both as-prepared MNC-20 anode and MLC-20 cathode achieves high reversible areal capacity of≈5.4 m A h cm^(-2)@0.1 C and outstanding Li-ion diffusion coefficients of≈10~(-8)cm~2 s~(-1)in the half-cell configuration.The assembled MNC-20‖MLC-20 full cell LIB delivers maximum energy and power densities of244.04 W h kg^(-1)and 108.86 W kg^(-1),respectively.The excellent electrochemical properties of the asprepared thick electrodes can be attributed to the highly conductive,mechanical compactness and multidimensional mutual effects of the MCF,CNT and active materials that facilitates rapid Li-ion diffusion kinetics.Furthermore,electrochemical impedance spectroscopy(EIS),symmetric cells analysis,and insitu Raman techniques clearly validates the enhanced Li-ion diffusion kinetics in the present architecture.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(Ministry of Science and ICT(RS-2023-00254424)Ministry of Education(2020R1A6A1A03038540))。
文摘This review highlights the importance of recovering valuable metals from spent Li-ion battery(LIB)cathodes through the resynthesis of cathode active materials(CAMs).The resynthesis process of CAMs,a promising recycling method that directly produces CAM precursors from LIB leachate,is explored.This process encompasses six key steps,including pretreatment,leaching,purification,adjustment of metal concentrations,precursor synthesis,and sintering.The review also investigates the potential introduction of impurity elements during CAM resynthesis and provides tolerance levels for these impurities based on thorough reference analysis.Additionally,it addresses challenges related to the commercialization of the resynthesis process.Notably,this review represents the first comprehensive assessment of CAM resynthesis,including the systematic evaluation of 12 impurity elements(Fe,Li,Al,Cu,C,P,F,Na,Cl,S,Mg,and Zn).Overall,this comprehensive review is poised to support the commercial development of resynthesized CAMs by offering valuable guidelines for managing impurities and streamlining the purification process.
基金National Natural Science Foundation of China (Grant Nos. 22379077 and 22005163)。
文摘The electrochromic Li-ion batteries(ELIBs) combine the functions of electrochromism and energy storage,realizing the display of energy-storage levels by visual signals. However, the accompanying interfacial issues including physical contact and(electro)chemical stability should be taken into account when the conventional liquid/gel electrolytes are replaced with solid-state counterparts. Herein, the in-situ liquid-solid transitional succinonitrile(SCN) plastic glues are constructed between electrodes and poly(ethylene oxide)(PEO) polymer electrolytes, enabling an interface-reinforced solid-state ELIB.Specifically, the liquid SCN precursor can adequately wet electrode/PEO interfaces at high temperature,while it returns back to solid state at room temperature, leading to seamless interfacial contact and smooth ionic transfer without changing the solid state of the device. Moreover, the SCN interlayer suppresses the direct contact of PEO with electrodes containing high-valence metal ions, evoking the improved interfacial stability by inhibiting the oxidation of PEO. Therefore, the resultant solid-state ELIB with configuration of LiMn_(2)O_(4)/SCN-PEO-SCN/WO_(3) delivers an initial discharge capacity of 111 m A h g^(-1) along with a capacity retention of 88.3% after 200 cycles at 30 ℃. Meanwhile, the electrochromic function is integrated into the device by distinguishing its energy-storage levels through distinct color changes. This work proposes a promising solid-state ELIB with greatly reinforced interfacial compatibility by introducing in-situ solidified plastic glues.
基金financially supported by the National Natural Science Foundation of China(Grant No.22273096)the Fundamental Research Funds for Central Universities(20826041G4185)
文摘To achieve high-energy-density and safe lithium-metal batteries(LMBs),solid-state electrolytes(SSEs)that exhibit fast Li-ion conductivity and good stability against lithium metal are of great importance.This study presents a systematic exploration of selenide-based materials as potential SSE candidates.Initially,Li_(8)SeN_(2)and Li_(7)PSe_(6)were selected from 25 ternary selenides based on their ability to form stable interfaces with lithium metal.Subsequently,their favorable electronic insulation and mechanical properties were verified.Furthermore,extensive theoretical investigations were conducted to elucidate the fundamental mechanisms underlying Li-ion migration in Li_(8)SeN_(2),Li_(7)PSe_(6),and derived Li_(6)PSe_(5)X(X=Cl,Br,I).Notably,the highly favorable Li-ion conduction mechanism of vacancy diffusion was identified in Li6PSe5Cl and Li_(7)PSe_(6),which exhibited remarkably low activation energies of 0.21 and 0.23 eV,and conductivity values of 3.85×10^(-2)and 2.47×10^(-2)S cm^(-1)at 300 K,respectively.In contrast,Li-ion migration in Li_(8)SeN_(2)was found to occur via a substitution mechanism with a significant diffusion energy barrier,resulting in a high activation energy and low Li-ion conductivity of 0.54 eV and 3.6×10^(-6)S cm^(-1),respectively.Throughout this study,it was found that the ab initio molecular dynamics and nudged elastic band methods are complementary in revealing the Li-ion conduction mechanisms.Utilizing both methods proved to be efficient,as relying on only one of them would be insufficient.The discoveries made and methodology presented in this work lay a solid foundation and provide valuable insights for future research on SSEs for LMBs.
基金Project supported by the Science Fund of the Guangdong Major Project of Basic and Applied Basic Research,China(Grant No.2019B030302011)the Fund of the Science and Technology Program of Guangzhou,China(Grant No.202201010090)。
文摘Combining the first-principles calculations and structural enumeration with recognition,the delithiation process of LiNiO_(2)is investigated,where various supercell shapes are considered in order to obtain the formation energy of Li_(x)NiO_(2).Meanwhile,the voltage profile is simulated and the ordered phases of lithium vacancies corresponding to concentrations of 1/4,2/5,3/7,1/2,2/3,3/4,5/6,and 6/7 are predicted.To understand the capacity decay in the experiment during the charge/discharge cycles,deoxygenation and Li/Ni antisite defects are calculated,revealing that the chains of oxygen vacancies will be energetically preferrable.It can be inferred that in the absence of oxygen atom in high delithiate state,the diffusion of Ni atoms is facilitated and the formation of Li/Ni antisite is induced.
基金based upon research funded by the Iran National Science Foundation. (INSF)under project No.4022382 and 4025075。
文摘Two-dimensional(2D)metal-organic frameworks(MOFs)are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily available active sites,and versatile,adaptable structures.These promising characteristics have positioned them as highly appealing alternatives for a wide range of applications in energy storage technologies,including lithium batteries.Nevertheless,the poor conductivity and limited stability of 2D MOFs have limited their real applications in electrochemical energy storage.These limitations have therefore warranted ongoing research to enhance the performance of 2D MOFs.Given the significance of 2D MOF-based materials as an emerging class of advanced materials,a multitude of strategy has been devised to address these challenges such as synthesizing 2D conductive MOFs and derivatives along with 2D MOF hybridization.One promising approach involves the use of 2D MOF derivatives,including transition metal oxides,which due to their abundant unsatu rated active metal sites and shorter diffusion paths,offer superior electrochemical performance.Additionally,by combining pristine 2D MOFs with other materials,hybrid 2D MOF materials can be created.These hybrids,with their enhanced stability and conductivity,can be directly utilized as active materials in lithium batteries.In the present review,we categorize 2D MOF-based materials into three distinct groups:pristine 2D MOFs,2D MOFderived materials,and 2D MOF hybrid materials.The synthesis methods for each group,along with their specific applications as electrode materials in lithium-ion batteries,are discussed in detail.This comprehensive review provides insights into the potential of 2D MOFs while highlighting the opportunities and challenges that are present in this evolving field.
文摘One of the new methods for ensuring that the battery in a thermal energy storage system is kept at the proper temperature is the heat pipe-based ThermalManagement System(TMS).In this study,the improvement of cooling performance of a heat pipe based TMS is examined through the variation of condenser section length of heat pipes in an array.The TMSs with an array of heat pipes with different condenser section lengths are considered.The system performances are evaluated using a validated numerical method.The results show that a heat pipebased TMS provides the best cooling performance when a wavy-like variation is employed and when the condenser section length of the last set of the heat pipe in the array is greater than that of the penultimate set.The maximum cell temperature and the maximum temperature difference within the cell of this TMS are decreased by 4.2 K and 1.1 K,respectively,when compared to the typical heat pipe based TMS with zero variation in its condenser section length.Conclusively,the strategy offers an improvement in the thermal uniformity for all the TMS cases.
文摘该实验采用乙二胺四乙酸二钠(EDTA-2Na)-磷酸(2 g-5 m L)蒸馏体系对高粱、大曲、酒醅中的氰化物进行蒸馏提取,并结合全自动流动注射分析技术建立了高粱、大曲、酒醅中氰化物的快速测定方法。结果表明,氰化物在5~200μg/L范围内具有良好的线性关系(R2=0.999 6),检出限(LOD)为8.10μg/kg,定量限(LOQ)为25.00μg/kg;精密度、重复性、稳定性均良好,相对标准偏差(RSD)均<10%;样品的加标回收率为82.23%~97.64%。该检测技术前处理简便,检测效率较高,定量结果准确可靠,适用于大批量高粱、大曲、酒醅样品中氰化物的检测分析,对于提升白酒的质量安全监测能力具有重要的实际意义。
基金supported by a research program through the National Research Foundation of Korea (NRF),funded by MSIT and MEST (NRF-2018R1A5A1025594,NRF-2021R1A4A1022198,and 2022R1A2B5B01001943)。
文摘We propose a method for producing composite materials(hTNO@C_(60))comprising crystalline C_(60)particles and hollow-structu red TiNb_(2)O_(7)(hTNO)nanofibers via facile liquid-liquid interface precipitation followed by low-temperature annealing.This allows the systematic design of crystalline C_(60)as an active material for Li-ion battery anodes.The hTNO@C_(60)composite demonstrates outstanding cyclic stability,retaining a capacity of 465 mA h g^(-1)after 1,000 cycles at 1 A g^(-1)It maintains a capacity of 98 mA h g^(-1)even after16,000 ultralong cycles at 8 A g^(-1)The enhancement in electrochemical properties is attributed to the successful growth and uniform doping of crystalline C_(60),resulting in improved electrical conductivity.The excellent electrochemical stability and properties of these composites make them promising anode materials.
文摘A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage (CC- CV) charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the beginning, and then the charging current begins to decrease before the battery voltage reaches its final value. After the battery voltage reaches its final value and remains constant,the charging current is further reduced. This approach prevents charging the battery with full current near its saturated voltage,which can cause heating. The novel design of the core of the charger IC realizes the proposed CC-CV charge mode. The chip was implemented in a CSMC 0.6μm CMOS mixed signal process. The experimental results verify the realization of the proposed CC- CV charge mode. The voltage of the battery after charging is 4. 1833V.