Cu2SnSe3/CNTs Composite as a Promising Anode Material for Sodium-ion Batteries

Metal selenides as anode materials for sodium-ion batteries have attracted considerable attention owing to their high theoretical specific capacities and variable composition and structures.However,the achievement of long cycle life and superior rate performance is challenging for these selenide materials due to the volume variation upon cycling.Herein,a composite composed of a new binary-metal selenide[Cu2SnSe3(CSS)]and carbon nanotubes(CNTs)was constructed via a hydrothermal process followed by calcination at 600℃.Benefited from the unique structure of binary-metal selenide and the conductive network of CNTs,the Cu2SnSe3/carbon nanotubes(CSS/CNT)composite exhibits excellent electrochemical performance when used as an anode material for sodium-ion batteries.A reversible specific capacity of 399 mA·h/g can be maintained at a current density of 100 mA/g even after 100 cycles.This work provides a promising strategy for rational design of binary-metal selenides upon delicate crystal phase control as electrode materials.     

中空碳材料用于钠离子电池负极的研究进展

实现钠离子电池等储能设备的大规模应用对于能源的可持续发展以及完成“碳达峰碳中和”目标具有重要意义.开发高性能的负极材料可提升钠离子电池的能量密度和循环稳定性,是实现钠离子电池大规模应用的关键性因素.中空碳材料因其独特的结构而具有优异的倍率性能与循环稳定性,作为钠离子负极材料具有广阔的应用前景.本文从多角度出发,综合评述了中空碳材料的合成方法,以及其形貌、杂原子修饰策略与储钠性能之间的关系,并对其未来发展方向进行了展望.     

Bimetallic Sulfide/Sulfur Doped T3C2Tx MXene Nanocomposites as High-performance Anode Materials for Sodium-ion Batteries

The application of transition metal dichalcogenides(TMDs) as anode materials in sodium-ion batteries (SIBs) has been hindered by low conductivity and poor cyclability. Herein, we report the synthesis of Co_xFe_1-xS₂ bimetallic sulfide/sulfur-doped Ti₃C₂ MXene nanocomposites(Co_xFe_1-xS₂@S-Ti₃C₂) by a facile co-precipitation process and thermal-sulfurization reaction. The interconnected 3D frameworks consisting of MXene nanosheets can effectively buffer the volume change and enhance the charge transfer. In particular, sulfur-doped MXene nanosheets provide rich active sites for sodium storage and restrain sulfur loss during charging/discharging processes, leading the increase of specific capacity and cycling the stability of anode materials. As a result, Co_xFe_1-xS₂@S-Ti₃C₂ anodes exhibited high capacity, high rate capability and long cycle life(399 mA·h/g at 5 A/g with an 94% capacity retention after 600 cycles).     

钠离子电池炭基负极材料研究进展

钠离子电池是目前新兴的低成本储能技术,因在大规模电化学储能中具有较好的应用前景而受到了国内外学者广泛的关注与研究。作为钠离子电池的关键电极材料之一,非石墨的炭质材料因具有储钠活性高、成本低廉、无毒无害等诸多优点,而被认为是钠离子电池实际应用时负极的最佳选择。本文详细综述了目前钠离子电池炭基负极材料的研究进展,重点介绍了炭质材料的储钠机理与特性,分析了炭材料结构与电化学性能之间的关系,探讨了其存在的问题,为钠离子电池炭基负极材料的发展提供有益的认识。     

NiCo_2S_4六角片作为钠离子电池负极材料的电化学性能及储钠动力学

通过共沉淀以及后续的气相硫化成功制备了横向边长约为2μm,纵向厚度约为30 nm的NiCo_2S_4六角片,并研究了其作为钠离子电池负极材料的电化学性能。电化学性能测试结果显示在1000 mA·g~(-1)的电流密度下,NiCo_2S_4电极循环60次后仍然可保持约387mAh·g~(-1)的可逆比容量。此外,NiCo_2S_4电极还具有良好的倍率性能,在200、400、800、1000和2000mA·g~(-1)的电流密度下,容量分别为542、398、347、300和217mAh·g~(-1)。通过进一步动力学机制分析发现,NiCo_2S_4电极的良好的倍率性能得益于其二维片层状结构诱导产生的赝电容。上述结果表明,NiCo_2S_4纳米六角片是一种极具潜力的钠离子电池负极材料。     

碳包覆纳米SnSb合金作为高性能钠离子电池负极材料

采用喷雾热解法合成了碳包覆的SnSb/C合金复合材料,利用X射线粉末衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)等方法对产物的物相和形貌进行了表征,其中SnSb/C颗粒为10 nm左右的复合材料(10-SnSb/C)作为钠离子电池负极时,表现出优异的循环和倍率性能。首圈放电达到722.1m Ah·g~(-1),首圈库仑效率86.3%,在100、1000、3000 m A·g~(-1)下比容量分别为607.7、645.4、452.2 m Ah·g~(-1),在1000 m A·g~(-1)电流下循环200周后可逆容量达到623 m Ah·g~(-1),容量保持率为95%。SnSb/C复合材料出色的储钠性能源于其完全被碳包裹的纳米结构,该结构可以有效提高活性物质的利用率,促进电子、离子的传导,并且抑制纳米粒子在长循环过程中的粉化和团聚。     

钠离子电池磷酸盐正极材料研究进展

近年来,钠离子电池因其原材料丰富、资源成本低廉及安全环保等突出优点,在电化学规模储能领域和低速电动车中具有广阔的应用前景。聚阴离子型磷酸盐具有稳定的框架结构、合适的工作电压和快速的离子扩散路径等特征,是一类极具研究价值和应用前景的钠离子电池正极材料。但是,磷酸盐正极材料电子导电性差和比能量偏低等缺陷限制了其走向实际应用。研究工作者通过体相结构调控和微纳结构设计等手段进行改性研究,旨在提升磷酸盐正极材料的性能表现、推动钠离子储能体系的研究开发。本文综述了钠离子电池磷酸盐正极材料的最新进展,包括正磷酸盐、焦磷酸盐、氟磷酸盐和混合磷酸盐化合物,通过对磷酸盐材料的晶体结构、储钠机理和改性策略等方面的综述,揭示材料成分、结构与电化学性能之间的本征关系,为聚阴离子磷酸盐正极材料的持续改性和新型磷酸盐高压正极材料的探索开发提供指导。     

Synthesis of SnS2 Ultrathin Nanosheets as Anode Materials for Potassium Ion Batteries

Potassium(K)ion batteries present their promising application for large-scale energy storage systems with cost-effective characteristic.Unfortunately,the large K ion radius results in sluggish K ion diffusion kinetics and volume expansion of the electrode during the K ion insertion/extraction process.It is a challenge to explore capable anode materials with remarkable K ion storage ability.Herein,we design and prepare SnS2 ultrathin nanosheets via a facile hydrothermal process.When severing as anode materials for K ion batteries with optimized electrolyte,SnS2 presents an improved capacity and rate ability.The capable electrochemical performance is ascribed to the reduced ion diffusion pathway and capacitor-dominated K-ion storage process.In addition,the K ion storage mechanism of SnS2 is investigated by the ex-situ X-ray diffraction technique.     

FeBO3 as a low cost and high-performance anode material for sodium-ion batteries

The research of borate materials as sodium-ion batteries (SIBs) anode is still in the early stages, but the boron polyoxoanions are attracting intense interest due to their low atomic weight and high electronegative features. In this work, FeBO₃ was prepared with low-cost raw materials and evaluated as SIBs anode. The FeBO₃ shows a high reversible capacity of 328 mAh/g at the current density of 0.4 A/g. In addition, the electrochemical performance of FeBO₃ can be improved by carbon coating. The prepared carbon-coated FeBO₃ composite has a reversible capacity of 426 mAh/g (at 0.4 A/g) and an outstanding rate capability of 272 mAh/g (at 1.6 A/g). Furthermore, the sodium storage mechanism of FeBO₃ was studied by in-situ XRD and ex-situ XPS.     

核壳结构金属-有机骨架及其衍生物在锂离子电池负极材料中的应用

金属-有机骨架(MOFs)材料具有比表面积较大、孔径可调、制备容易、结构与功能多样性等优势,被广泛应用于电化学能源转化与储存领域。其中独特的核壳结构材料由于表面修饰的作用往往更能表现出内核与壳层之间的协同作用。本文介绍了核壳结构MOFs作为锂离子电池负极材料的发展现状,并重点综述其衍生物(多孔碳材料、金属氧化物、金属硫/硒化物以及金属/金属氧化物)的制备方法以及在锂离子电池负极中的应用。MOFs经高温煅烧或改变化学反应条件可制备出结构可调的无机电极材料并表现出更优异的电化学性能。最后总结了核壳结构MOFs材料作为锂电负极材料存在的问题和挑战,并提出可能的解决途径和未来的应用前景。     

钠离子电池用高性能锑基负极材料的调控策略研究进展

锑(Sb)具有高的理论比容量、较小的电极极化、合适的Na⁺脱嵌电位、价格低廉以及环境友好的优势,而成为一种具有较大应用前景的钠离子电池负极材料。但是,Sb基负极材料的一个重要挑战是在循环过程中高比容量伴随着大的体积变化,进而导致活性材料粉化,并从集流体上脱落,这大大限制了其在钠离子电池领域的大规模应用。因此,如何解决Sb基负极材料充放电过程中体积膨胀问题对于高性能的钠离子电池设计是至关重要的。本文详细综述和讨论了Sb基材料的结构-性能关系及其在钠离子电池中的应用,详细介绍了钠离子电池Sb基负极材料在氧化还原反应机理、形貌设计、结构-性能关系等方面的最新研究进展。本综述的主要目的是探讨影响Sb基负极材料性能的决定因素,从而提出有前途的改性策略,以提高其可逆容量和循环稳定性。最后,对Sb基钠离子电池负极材料的未来发展、面临的挑战和前景进行了展望。本文可为Sb负极材料的构建和优化提供具体的观点,阐明了Sb基负极材料未来的发展方向,从而促进钠离子电池的快速发展和实际应用。     

钠离子电池用高性能锑基负极材料的调控策略研究进展

Na-ion batteries (SIBs) are promising alternatives for Li-ion batteries owing to the natural abundance of sodium resources and similar energy storage mechanisms. Although significant progress has been achieved in research on SIBs, there remain several challenges to be addressed. One of the major challenges in the construction of high-performance SIBs is the development of suitable anode materials with a large reversible capacity, high cycling stability, and good rate performance. Alloying anode materials mainly composed of elements from Groups IVA and VA, as well as their alloys, have attracted widespread attention because of their low working voltage, high cost-effectiveness, and large theoretical capacity. Alloying-type anode materials can be alloyed with metallic Na to achieve large reversible capacities, ensuring a high energy density. Antimony is a promising anode material for SIBs owing to its high theoretical specific capacity (660 mAh·g⁻¹, corresponding to the full sodiation Na₃Sb alloy), small degree of electrode polarization (~0.25 V), appropriate Na⁺ deintercalation potential (0.5–0.75 V), low price, and environmental friendliness. However, an important challenge for using Sb-based anode materials is that the high specific capacity is accompanied by large volume changes during cycling. Such changes lead to the pulverization of the active materials and their falling off from the collector, which significantly limit their large-scale application in the field of sodium-ion batteries. Therefore, mitigating the volume expansion issue of Sb-based anode materials in the charge-discharge process is very important for the design of high-performance SIBs. In recent years, researchers have attempted to address this issue by designing special structures to prepare various composites, and substantial progress has been achieved in improving the electrochemical performance of SIBs. In this review, the relationship between the structure and properties of Sb-based materials and their applications in SIBs are presented and discussed in detail. The latest research progress on using Sb-based anode materials for SIBs in redox reaction mechanisms along with their morphology design, structure-performance relationship, etc. have been reviewed. The main objective of this review is to explore the determining factors of the performance of Sb-based anode materials to propose suitable modification strategies for improving their reversible capacity and cycle stability. Finally, future developments, challenges, and prospects of Sb-based anode materials for SIBs are discussed. Despite several challenges, Sb-based materials are very promising anode materials for SIBs with alloying reaction mechanisms. To further improve the large-scale application of Sb-based anode materials, it is necessary to optimize the binder, electrode structure, and electrolyte composition. The combination of in-depth studies on the electrochemical reaction mechanisms and advanced characterization technologies is important for the development and construction of advanced Sb-based anode materials for SIBs. Finally, to achieve extensive large-scale applications, it is necessary to further explore environmentally friendly, low-cost, and controllable synthetic technologies to prepare high-performance Sb-based anode materials. This review provides specific perspectives for the construction and optimization of Sb-based anode materials and suggests scope for future work on Sb-based anode materials, thereby promoting the rapid development and practical application of SIBs.      

Improved Initial Charging Capacity of Na-poor Na0.44MnO2 via Chemical Presodiation Strategy for Low-cost Sodium-ion Batteries

Sodium-ion batteries(SIBs)are promising for grid-scale energy storage applications due to the natural abundance and low cost of sodium.Among various Na insertion cathode materials,Na0.44MnO2 has attracted the most attention because of its cost effectiveness and structural stability.However,the low initial charge capacity for Na-poor Na0.44MnO2 hinders its practical applications.Herein,we developed a facile chemical presodiated method using sodiated biphenly to transform Na-poor Na0.44MnO2 into Na-rich Na0.66MnO2.After presodiation,the initial charge capacity of Na0.44MnO2 is greatly enhanced from 56.5 mA·h/g to 115.7 mA·h/g at 0.1 C(1 C=121 mA/g)and the excellent cycling stability(the capacity retention of 94.1%over 200 cycles at 2 C)is achieved.This presodiation strategy would open a new avenue for promoting the practical applications of Na-poor cathode materials in sodium-ion batteries.     

水热法制备Fe3O4/rGO纳米复合物作为锂离子电池阳极材料

以氢氧化铁为四氧化三铁的前驱体,氧化石墨烯（GO）为还原石墨烯（rGO）的前驱体,以水合肼和二水合柠檬酸三钠为混合还原剂,采用水热法制备了还原石墨烯负载四氧化三铁纳米颗粒（Fe₃O₄/rGO）的复合材料。通过透射电子显微镜（TEM）、X-射线衍射（XRD）和热重分析（TGA）对产物的形貌、结构和组成进行了表征。以锂片为对电极进行了扣式电池的组装,通过恒电流充放电和循环伏安法对其电化学性能进行了测试。材料具有均一的形貌,rGO具有较高的还原程度且可以在充放电过程中缓冲Fe₃O₄纳米颗粒的体积变化,使得Fe₃O₄/rGO纳米复合物具有较好的电化学性能。     

锂离子电池高比容量FeSn_2-C复合负极材料的合成与性能

Sn基合金负极材料具有高达990 mAh·g-1的理论比容量,但其也存在因脱嵌锂过程发生巨大的体积变化而导致循环性能较差的问题.本文以Sn、Fe、石墨为原料利用简易的高能球磨法成功制备了具有核壳结构的FeSn2-C复合物,系统研究了球磨时间、FeSn2相含量对材料物相结构及电化学性能的影响,并分析了电极的失效机理.研究表明,球磨时间的增加有利于FeSn2金属间化合物相的形成及材料颗粒的细化,进而有利于材料比容量的增加及循环性能的提升;FeSn2相含量的增加能够提高FeSn2-C材料的比容量,但会降低FeSn2-C电极的循环稳定性.经工艺优化及组分调节,球磨24 h合成的Sn20Fe10C70材料具有最优的电化学性能,材料的比容量在540mAh·g-1左右,并能稳定循环100次,是一种非常有发展前途的锂离子电池高比容量负极材料.     

Bismuth Nanoparticles Anchored on Ti3C2Tx MXene Nanosheets for High-Performance Sodium-Ion Batteries

Sodium-ion batteries are promising energy-storage systems, but they are facing huge challenges for developing fast-charging anode materials. Bismuth (Bi)-based anode materials are considered as candidates for fast-charging anodes of sodium-ion batteries due to their excellent rate performance. Herein, we designed a two-dimensional Bi/MXene anode material based on a hydrogen thermal reduction strategy. Benefitting from microstructure advantages, Bi/MXene anodes exhibited an excellent rate capability and superior cycle performance in Na//Bi/MXene half-batteries and Na₃V₂(PO₄)₃/C//Bi/MXene full-batteries. Moreover, full-batteries can complete a charge/discharge cycle in 7 min and maintain an excellent cycle life (over 7000 cycles). The electrochemical test results showed that Bi/MXene is a promising anode material with fast charge/discharge capability for sodium-ion batteries.     

Nitrogen Doped Carbon Coated Bi Microspheres as High-performance Anode for Half and Full Sodium Ion Batteries

As two-dimensional (2D) materials, bismuth (Bi) has large interlayer spacing along c-axis (0.395 nm) which provides rich active sites for sodium ions, thus guaranteeing high sodium ion storage activity. However, its poor electrical conductivity, combined with its degraded cycling performance, restricts its practical application. Herein, Bi microsphere coated with nitrogen-doped carbon (Bi@NC) was synthesized. Owing to the unique Bi crystals and nitrogen-doped carbon layer, the obtained Bi@NC anode exhibited satisfactory cycling stability and superior rate capability. Moreover, after assembling Bi@NC anode with Na₃V₂(PO₄)₃@C cathode to full battery, excellent sodium storage performance was obtained (57 mA h g⁻¹ after 2000 cycles at 1.0 A g⁻¹).     

锂离子电池TiO2纳米管负极材料

锂离子电池负极材料二氧化钛(TiO₂)由于其零应变、环境友好和高安全性近年来得到了广泛的研究,但其较低的电子电导和离子迁移率以及较低的比容量(335 mAh·g^-1)限制了其应用前景.本文梳理了一种纳米结构TiO₂纳米管(TNTs)的研究历程以及最近研究进展,综述了TNTs常见的几种制备方法,即水热法、阳极氧化法和模板法及其形成机理,归纳了各种制备方法的优缺点,讨论了制备过程中各项参量对制得TNTs的影响.阐述了其晶体结构与形貌对电化学性能的影响,指出晶格取向一致、管壁厚度小,纳米管开口且同向排列的TNTs具有更好的电化学性能.同时探讨了针对该材料电导性差、比容量低而进行的包括结构设计、掺杂、复合等一系列改进措施,指出与高电导率及高比容量材料复合是一种方便有效的改进措施.最后总结了各种改性方法取得的进展及存在的不足,展望了TNTs的研究趋势和发展前景.     

纳米MnO锂离子电池负极材料的制备与性能

以高锰酸钾和抗坏血酸合成的MnC₂O₄·2H₂O为前驱体, 通过固相烧结制备了纳米MnO材料. 分别采用X射线衍射(XRD)、扫描电子显微镜(SEM)和恒电流充放电技术考察了其晶相结构、颗粒形貌和电化学性能.分析结果表明, 该纳米MnO具有面心立方的岩盐结构, 结晶度良好. 其颗粒是由粒径为50-100 nm的一次颗粒结合而成的二次颗粒, 大小约为400-600 nm. 当充放电电流密度为46.3 mA·g^-1时, 纳米MnO的首次库仑效率可达68.9%, 可逆比容量为679.7 mAh·g^-1. 在141.1 mA·g^-1的电流密度下循环50圈后, 比容量由584.5mAh·g^-1降至581.5 mAh·g^-1, 容量保持率高达99.5%, 表现出优异的循环性能. 此外, 当电流密度增加到494.7 mA·g^-1 (~2C)时, 其比容量依然可达290 mAh·g^-1, 表现出较好的倍率性能和快速充放电能力. 因此, 纳米MnO具有比容量高、循环稳定、倍率性能好和安全环保等优点,是一种非常有前景的锂离子电池负极材料.     

过渡金属二硼化物作为高容量负极的研究

碱性溶液中,VB2和TiB2分别发生了 11电子和 6电子氧化反应,释放出 3 100mAh/g和 1 600mAh/g的超常电化学容量.对此,初步的解释是:在二硼化物中过渡金属与硼的电子转移使硼元素电负性增强,引起硼的电化学活化.使得合金的电极电势钳制在较负区域,导致某些过渡金属元素处于活化态,进而发生电化学氧化释放出电化学能量.