Carbon materials,including graphite,hard carbon,soft carbon,graphene,and carbon nanotubes,are widely used as high-performance negative electrodes for sodium-ion and potassium-ion batteries(SIBs and PIBs).Compared with...Carbon materials,including graphite,hard carbon,soft carbon,graphene,and carbon nanotubes,are widely used as high-performance negative electrodes for sodium-ion and potassium-ion batteries(SIBs and PIBs).Compared with other materials,carbon materials are abundant,low-cost,and environmentally friendly,and have excellent electrochemical properties,which make them especially suitable for negative electrode materials of SIBs and PIBs.Compared with traditional carbon materials,modifications of the morphology and size of nanomaterials represent effective strategies to improve the quality of electrode materials.Different nanostructures make different contributions toward improving the electrochemical performance of electrode materials,so the synthesis of nanomaterials is promising for controlling the morphology and size of electrode materials.This paper reviews the progress made and challenges in the use of carbon materials as negative electrode materials for SIBs and PIBs in recent years.The differences in Na+and K+storage mechanisms among different types of carbon materials are emphasized.展开更多
Rhenium diselenide(ReSe2) has caused considerable concerns in the field of energy storage because the compound and its composites still suffer from low specific capacity and inferior cyclic stability.In this study,ReS...Rhenium diselenide(ReSe2) has caused considerable concerns in the field of energy storage because the compound and its composites still suffer from low specific capacity and inferior cyclic stability.In this study,ReSe2 nanoparticles encapsulated in carbon nanofibers were synthesized successfully with simple electrospinning and heat treatment.It was found that graphene modifications could affect considerably the microstructure and electrochemical properties of ReSe2–carbon nanofibers.Accordingly,the modified compound maintained a capacity of 227 mAhg-1 after 500cycles at 200 mAg-1 for Na+storage,230 mAh g-1 after 200 cycles at 200 mAg-1,212 mAh g-1 after 150 cycles at 500 mAg-1 for K+ storage,which corresponded to the capacity retention ratios of 89%,97%,and 86%,respectively.Even in Na+full cells,its capacity was maintained to 82% after 200 cycles at 1 C(117 mAg-1).The superior stability of ReSe2–carbon nanofibers benefitted from the extremely weak van der Waals interactions and large interlayer spacing of ReSe2,in association with the role of graphene-modified carbon nanofibers,in terms of the shortening of electron/ion transport paths and the improvement of structural support.This study may provide a new route for a broadened range of applications of other rhenium-based compounds.展开更多
Two-dimensional(2D)nanomaterials,such as graphene,MoS_(2),and MAX,have attracted increasing research attention in recent years due to their unique structural and performance advantages.However,their complex production...Two-dimensional(2D)nanomaterials,such as graphene,MoS_(2),and MAX,have attracted increasing research attention in recent years due to their unique structural and performance advantages.However,their complex production processes and equipment requirements are significant issues affecting their widespread use.Here,with an exfoliation strategy using three-roll milling,we present a simple,cost-effective,and extensible method to produce multilayer graphene,BN,MoS_(2),and Ti_(3)AlC_(2) nanosheets.The roller and phenolic resin created three kinds of forces on the layered 2D materials,i.e.,shear forces,compressive forces,and adhesive forces,which exfoliated layered materials from their edges and surfaces into nanosheets.Subsequently,the exfoliated materials were ultrasonically washed with alcohol,treated with ultrasonic vibration,and centrifuged to obtain 2D nanomaterials.The easy operation and high yield are attractive for research based on the construction of high-performance 2D nanosheet-based devices at low cost.Herein,the obtained multilayer graphene and MoS_(2) nanosheets were used as anode materials of sodium/potassium-ion batteries,respectively,to test their electrochemical properties.Better performances are obtained compared with their primary bulk materials.展开更多
Developing electrodes with long lifespan and wide-temperature adaptability is crucial important to achieve high-performance sodium/potassium-ion batteries(SIBs/PIBs).Herein,the SnSe2-SePAN composite was fabricated for...Developing electrodes with long lifespan and wide-temperature adaptability is crucial important to achieve high-performance sodium/potassium-ion batteries(SIBs/PIBs).Herein,the SnSe2-SePAN composite was fabricated for extraordinarily stable and wide-temperature range SIBs/PIBs through a coupling strategy between controllable electrospinning and selenylation,in which SnSe2 nanoparticles were uniformly encapsulated in the SePAN matrix.The unique structure of SnSe2-SePAN not only relieves drastic volume variation but also guarantees the structural integrity of the composite,endowing SnSe2-SePAN with excellent sodium/potassium storage properties.Consequently,SnSe2-SePAN displays a high sodium storage capacity and excellent feasibility in a wide working temperature range(-15 to 60℃:300 mAh g^(-1)/700 cycles/-15℃;352 mAh g^(-1)/100 cycles/60℃at 0.5 A g^(-1)).At room temperature,it delivers a record-ultralong cycling life of 192 mAh g^(-1)that exceeds 66000 cycles even at 15 A g^(-1).It exhibits extremely superb electrochemical performance in PIBs(157 mAh g^(-1)exceeding 15000 cycles at 5 A g^(-1)).The ex situ XRD and TEM results attest the conversion-alloy mechanism of SnSe2-SePAN.Also,computational calculations verify that SePAN takes an important role in intensifying the electrochemical performance of SnSe2-SePAN electrode.Therefore,this study breaks new ground on solving the polyselenide dissolution issue and improving the wide temperature workable performance of sodium/potassium storage.展开更多
Although organic electrode materials have merits of abundant resources,diverse structures and environmental friendliness,their performance for electrochemical energy storage is far insufficient.In this work,a thiourea...Although organic electrode materials have merits of abundant resources,diverse structures and environmental friendliness,their performance for electrochemical energy storage is far insufficient.In this work,a thiourea-based polyimide/reduced graphene oxide(PNTCSA/RGO)composite was synthesized via a condensation polymerization method.As a cathode material in lithium-ion batteries,excellent performance is demonstrated with high reversible capacity(144.2 mA h g^−1),high discharge voltage(∼2.5 V),and long cycling life(over 2000 cycles at 500 mA g^−1),which are comparable to those of other well documented in organic electrodes.Encouraging electrochemical performance is also demonstrated for sodium ion batteries(a cycling life of 800 cycles at 500 mA g^−1),while poor performance is delivered in potassium ion batteries.Theoretical studies reveal that the active sites are carbonyl groups for all alkali ions but one inserted alkali metal ion is shared by two carbonyl groups from the two neighbor units.More importantly,K ions have stronger interaction with S atoms than Li/Na ions,which may lead to poor structure reversibility and account for the poor cycling performance.Our findings provide a fundamental understanding of polyimide based polymer electrodes and help to design and develop high performance organic electrode materials for alkali metal ion batteries.展开更多
目的探讨神经元细胞KCC2、NKCC1及4E-BP1在外伤性癫痫致痫灶中的表达及其临床意义。方法选择2017年1月-2019年6月本院接诊外伤性癫痫患者37例纳入研究组,经手术切除癫痫致癫灶;同期,另选择于单纯脑外伤患者40例纳入对照组,分别于脑外伤...目的探讨神经元细胞KCC2、NKCC1及4E-BP1在外伤性癫痫致痫灶中的表达及其临床意义。方法选择2017年1月-2019年6月本院接诊外伤性癫痫患者37例纳入研究组,经手术切除癫痫致癫灶;同期,另选择于单纯脑外伤患者40例纳入对照组,分别于脑外伤后6 h内手术获取脑组织样本。通过蛋白质印迹法测定外伤性癫痫致癫灶中KCC2、NKCC1、4E-BP1表达,并利用RT-PCR法测定外伤性癫痫致癫灶中KCC2 m RNA、NKCC1 m RNA、4E-BP1m RNA相对表达量。结果蛋白质印迹法检测显示:研究组患者的神经元细胞KCC2相对灰度值低于对照组,差异有统计学意义(P <0.05);研究组患者的神经元细胞NKCC1、4E-BP1相对灰度值均高于对照组,差异有统计学意义(P <0.05);RT-PCR检测显示:研究组患者的致癫灶中KCC2 m RNA相对表达量低于对照组,差异有统计学意义(P <0.05);研究组患者的致癫灶中NKCC1 m RNA、4E-BP1 m RNA相对表达量均高于对照组,差异有统计学意义(P <0.05)。结论神经元细胞KCC2、NKCC1及4E-BP1为脑外伤后患者脑组织的组织学改变、癫痫反复发作主要分子机制;KCC2在外伤性癫痫致癫灶中表达异常降低,而神经元细胞NKCC1、4E-BP1的表达异常增高,可以作为外伤性癫痫致痫灶靶向诊断因子。展开更多
文摘Carbon materials,including graphite,hard carbon,soft carbon,graphene,and carbon nanotubes,are widely used as high-performance negative electrodes for sodium-ion and potassium-ion batteries(SIBs and PIBs).Compared with other materials,carbon materials are abundant,low-cost,and environmentally friendly,and have excellent electrochemical properties,which make them especially suitable for negative electrode materials of SIBs and PIBs.Compared with traditional carbon materials,modifications of the morphology and size of nanomaterials represent effective strategies to improve the quality of electrode materials.Different nanostructures make different contributions toward improving the electrochemical performance of electrode materials,so the synthesis of nanomaterials is promising for controlling the morphology and size of electrode materials.This paper reviews the progress made and challenges in the use of carbon materials as negative electrode materials for SIBs and PIBs in recent years.The differences in Na+and K+storage mechanisms among different types of carbon materials are emphasized.
基金supported by the National Natural Science Foundation of China(Grants51772082,51574117,and 51804106)the Research Projects of Degree and Graduate Education Teaching Reformation in Hunan Province(JG2018B031,JG2018A007)+1 种基金the Natural Science Foundation of Hunan Province(2019JJ30002,2019JJ50061)project funded by the China Postdoctoral Science Foundation(2017M610495,2018T110822)
文摘Rhenium diselenide(ReSe2) has caused considerable concerns in the field of energy storage because the compound and its composites still suffer from low specific capacity and inferior cyclic stability.In this study,ReSe2 nanoparticles encapsulated in carbon nanofibers were synthesized successfully with simple electrospinning and heat treatment.It was found that graphene modifications could affect considerably the microstructure and electrochemical properties of ReSe2–carbon nanofibers.Accordingly,the modified compound maintained a capacity of 227 mAhg-1 after 500cycles at 200 mAg-1 for Na+storage,230 mAh g-1 after 200 cycles at 200 mAg-1,212 mAh g-1 after 150 cycles at 500 mAg-1 for K+ storage,which corresponded to the capacity retention ratios of 89%,97%,and 86%,respectively.Even in Na+full cells,its capacity was maintained to 82% after 200 cycles at 1 C(117 mAg-1).The superior stability of ReSe2–carbon nanofibers benefitted from the extremely weak van der Waals interactions and large interlayer spacing of ReSe2,in association with the role of graphene-modified carbon nanofibers,in terms of the shortening of electron/ion transport paths and the improvement of structural support.This study may provide a new route for a broadened range of applications of other rhenium-based compounds.
基金supported by the National Natural Science Foundation of China(Grant Nos.52272063 and 22262024)Key Research and Development Program of Jiangxi Province(Grant No.20203BBE53066)+1 种基金Natural Science Foundation of Jiangxi Province(Grant No.20224BAB214037)Graduate Innovation Special Fund of Nanchang Hangkong University(Grant No.YC_(2)023-S683).
文摘Two-dimensional(2D)nanomaterials,such as graphene,MoS_(2),and MAX,have attracted increasing research attention in recent years due to their unique structural and performance advantages.However,their complex production processes and equipment requirements are significant issues affecting their widespread use.Here,with an exfoliation strategy using three-roll milling,we present a simple,cost-effective,and extensible method to produce multilayer graphene,BN,MoS_(2),and Ti_(3)AlC_(2) nanosheets.The roller and phenolic resin created three kinds of forces on the layered 2D materials,i.e.,shear forces,compressive forces,and adhesive forces,which exfoliated layered materials from their edges and surfaces into nanosheets.Subsequently,the exfoliated materials were ultrasonically washed with alcohol,treated with ultrasonic vibration,and centrifuged to obtain 2D nanomaterials.The easy operation and high yield are attractive for research based on the construction of high-performance 2D nanosheet-based devices at low cost.Herein,the obtained multilayer graphene and MoS_(2) nanosheets were used as anode materials of sodium/potassium-ion batteries,respectively,to test their electrochemical properties.Better performances are obtained compared with their primary bulk materials.
基金supported by the National Key R&D Program of China(2019YFC1904500)National Natural Science Foundation of China(NSFC 21875037 and 51502036)+3 种基金Department of Ecology and Environment of Fujian Province(2021R024)the Young Top Talent of Fujian Young Eagle Program,Educational Commission of Fujian Province(2022G02022)Natural Science Foundation of Fujian Province(2023J02013 and 2019J06015)Natural Science Foundation of Fuzhou City(2022-Y-004).
文摘Developing electrodes with long lifespan and wide-temperature adaptability is crucial important to achieve high-performance sodium/potassium-ion batteries(SIBs/PIBs).Herein,the SnSe2-SePAN composite was fabricated for extraordinarily stable and wide-temperature range SIBs/PIBs through a coupling strategy between controllable electrospinning and selenylation,in which SnSe2 nanoparticles were uniformly encapsulated in the SePAN matrix.The unique structure of SnSe2-SePAN not only relieves drastic volume variation but also guarantees the structural integrity of the composite,endowing SnSe2-SePAN with excellent sodium/potassium storage properties.Consequently,SnSe2-SePAN displays a high sodium storage capacity and excellent feasibility in a wide working temperature range(-15 to 60℃:300 mAh g^(-1)/700 cycles/-15℃;352 mAh g^(-1)/100 cycles/60℃at 0.5 A g^(-1)).At room temperature,it delivers a record-ultralong cycling life of 192 mAh g^(-1)that exceeds 66000 cycles even at 15 A g^(-1).It exhibits extremely superb electrochemical performance in PIBs(157 mAh g^(-1)exceeding 15000 cycles at 5 A g^(-1)).The ex situ XRD and TEM results attest the conversion-alloy mechanism of SnSe2-SePAN.Also,computational calculations verify that SePAN takes an important role in intensifying the electrochemical performance of SnSe2-SePAN electrode.Therefore,this study breaks new ground on solving the polyselenide dissolution issue and improving the wide temperature workable performance of sodium/potassium storage.
基金This work was financially supported by the National Natural Science Foundation of China(51672188 and 21703036).
文摘Although organic electrode materials have merits of abundant resources,diverse structures and environmental friendliness,their performance for electrochemical energy storage is far insufficient.In this work,a thiourea-based polyimide/reduced graphene oxide(PNTCSA/RGO)composite was synthesized via a condensation polymerization method.As a cathode material in lithium-ion batteries,excellent performance is demonstrated with high reversible capacity(144.2 mA h g^−1),high discharge voltage(∼2.5 V),and long cycling life(over 2000 cycles at 500 mA g^−1),which are comparable to those of other well documented in organic electrodes.Encouraging electrochemical performance is also demonstrated for sodium ion batteries(a cycling life of 800 cycles at 500 mA g^−1),while poor performance is delivered in potassium ion batteries.Theoretical studies reveal that the active sites are carbonyl groups for all alkali ions but one inserted alkali metal ion is shared by two carbonyl groups from the two neighbor units.More importantly,K ions have stronger interaction with S atoms than Li/Na ions,which may lead to poor structure reversibility and account for the poor cycling performance.Our findings provide a fundamental understanding of polyimide based polymer electrodes and help to design and develop high performance organic electrode materials for alkali metal ion batteries.
文摘目的探讨神经元细胞KCC2、NKCC1及4E-BP1在外伤性癫痫致痫灶中的表达及其临床意义。方法选择2017年1月-2019年6月本院接诊外伤性癫痫患者37例纳入研究组,经手术切除癫痫致癫灶;同期,另选择于单纯脑外伤患者40例纳入对照组,分别于脑外伤后6 h内手术获取脑组织样本。通过蛋白质印迹法测定外伤性癫痫致癫灶中KCC2、NKCC1、4E-BP1表达,并利用RT-PCR法测定外伤性癫痫致癫灶中KCC2 m RNA、NKCC1 m RNA、4E-BP1m RNA相对表达量。结果蛋白质印迹法检测显示:研究组患者的神经元细胞KCC2相对灰度值低于对照组,差异有统计学意义(P <0.05);研究组患者的神经元细胞NKCC1、4E-BP1相对灰度值均高于对照组,差异有统计学意义(P <0.05);RT-PCR检测显示:研究组患者的致癫灶中KCC2 m RNA相对表达量低于对照组,差异有统计学意义(P <0.05);研究组患者的致癫灶中NKCC1 m RNA、4E-BP1 m RNA相对表达量均高于对照组,差异有统计学意义(P <0.05)。结论神经元细胞KCC2、NKCC1及4E-BP1为脑外伤后患者脑组织的组织学改变、癫痫反复发作主要分子机制;KCC2在外伤性癫痫致癫灶中表达异常降低,而神经元细胞NKCC1、4E-BP1的表达异常增高,可以作为外伤性癫痫致痫灶靶向诊断因子。
