低温等离子体改性碳布用于水系锌离子电池负极

用低温等离子体改性碳布构建了具有长寿命的水系锌离子电池三维结构负极。负极表面疏松多孔的沉积层有利于电解液的渗入提高锌的利用率,且能够在充放电过程中容纳锌从而实现抑制锌枝晶延长电池使用寿命的目的。使用该负极组装的对称电池的寿命从360 h提高到480 h,与活性炭正极组装的全电池在1 A·g^-1的电流密度下循环800圈后的容量保持率为70%,远高于未经处理的20%。     

水系锌离子电池锌负极的研究进展

水系锌离子电池由于其高安全性、环境友好、低成本和高能量密度而成为大规模储能应用中最有前途的系统之一。与水系锌离子电池正极材料的大量研究相比,改善锌负极电化学性能的研究仍处于起步阶段。由于枝晶生长、自腐蚀和不可逆副产物的形成,锌负极面临循环性差和库仑效率低等挑战。为了弥补水系锌离子电池中锌负极的固有缺陷,近年来已经开发了一些有效策略,如负极和电解液之间的界面修饰、锌负极的结构设计以及电解液设计。介绍了锌负极的最新研究进展,对水系锌离子电池未来的研究和发展方向进行了展望。     

锌离子电池负极锌枝晶抑制的研究进展

近些年来,因为含有水电解液的锌离子电池（ZIBs）具有高安全性、环境友好性、低成本和高能量密度等优点而受到研究人员越来越多的关注。然而,锌离子电池负极的不稳定性阻碍了ZIBs在实际应用中的可靠部署。主要针对ZIBs负极存在的锌枝晶问题,先简单介绍了ZIBs的基本知识以及锌枝晶的发展。然后介绍了锌枝晶的形成和生长机理,并对锌枝晶的抑制策略从锌负极、电解液和隔膜三个方面在近年来的研究进展进行了综述。最后对锌枝晶抑制的三个方面进行了总结,并对未来在ZIBs负极锌枝晶抑制方面的研究方向进行了展望。     

碳材料改性锌负极的复合锌离子电池电化学性能的研究

采用涂布法分别将碳纳米管(CNT)和氧化石墨(GO)涂布在铜箔(Cu)上制成Cu/CNT和Cu/GO复合集流体,随后在复合集流体表面电沉积锌(Zn)制成Cu/CNT/Zn和Cu/GO/Zn复合电极作为锌负极,并通过扫描电子显微镜(SEM)观察微观形貌。结果表明,可以发现锌在两种复合集流体上均为不规则片状,且由于氧化石墨的尺寸大于碳纳米管,其表面的锌片尺寸也略大于碳纳米管表面的锌片尺寸。在电流密度为0.5 mA/cm~2的循环测试中,Cu/CNT/Zn||Cu/CNT/Zn复合对称电池保持极化电压在0.02 V以内正常运行了50 h,而Cu/GO/Zn||Cu/GO/Zn复合对称电池保持极化电压在0.04 V以内正常运行了160 h。在全电池的电化学性能测试中, MnO_2||Cu/CNT/Zn和MnO_2||Cu/GO/Zn复合锌离子电池均表现出高于MnO_2||Zn电池的容量。     

水系锌离子电池及关键材料研究进展

水系锌离子电池作为一种新型二次离子电池,因其低成本、高安全、环境友好以及高功率密度等特点,在大规模储能等领域具有广阔的应用前景。以本课题组在水系锌离子电池领域的研究成果为基础,结合国内外同行的最新研究工作,主要从正极材料、负极材料和电解液3个方面系统性地总结了水系锌离子电池的研究进展,凝练出当前该领域电池循环寿命短等瓶颈问题并提出了"单相反应机制"等解决思路,最后对高能量密度、高安全、长寿命水系锌离子电池未来的研究和发展方向进行了展望。     

铌掺杂锌离子电池正极材料的制备及电化学性能研究

以高锰酸钾和乙酸锰为原料,在利用液相共沉淀法合成二氧化锰的过程中加入草酸铌溶液来合成掺有Nb的二氧化锰。通过粉末X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等手段对合成的二氧化锰进行表征,发现掺杂Nb能够使粉末颗粒的粒径变小,但不改变材料的结构。通过将粉末材料制成锌离子电池的正极材料并组装扣式电池进行电化学测试,发现掺杂Nb离子能够提高锌离子电池的容量,在1 A/g的电池密度下掺杂Nb离子的电池放电比容量最高达到165.3 mA·h/g,相同条件下未掺杂Nb的电池放电比容量最高为146.6 mA·h/g,并且掺杂后电池的倍率性能和循环稳定性都比较优异。     

锌离子电池正极纳米片材料制备和电化学性能研究

锌离子电池是一种环保、廉价、安全的新型电池,它的电化学行为是正极二氧化锰通过锰的价态转换来存储二价锌离子。二氧化锰作为锌离子电池的正极材料,由于其比表面积大、导电性差等特点导致其容量并不能充分发挥。采用自反应反胶束法制备的二维超薄二氧化锰(Mn O2)纳米片作为一种储存锌离子的材料,从整体上提高锌离子电池的容量。以二维超薄二氧化锰(Mn O2)纳米片为正极的锌离子电池,当电流密度为0.1 A/g时,最高容量达到484.2 m A·h/g,接近锌离子电池的最大理论容量616 m A·h/g;当电流密度为5 A/g时,电池循环两百圈后的容量保持率也有80%,表现了很好的循环性能。     

锂离子电池锡/碳复合负极材料的制备及电化学性能研究

以二氧化锡和导电碳(Super P)为原料,通过高能球磨,采用高温固相法制得锡/碳复合材料作为锂离子电池负极材料。用XRD、SEM进行表征,并进行有关电化学性能测试,首次放电比容量高达566.4 mAh.g-1,循环性能得到了较大改善。     

本征安全水系锌离子电池的新进展：锌负极晶面调控

水系锌离子电池环境友好、成本低廉,是一种极具发展潜力、本征安全的电化学储能技术。对于实用化的锌离子电池,负极端金属锌的不均匀沉积所引起的枝晶问题会导致电池短路,严重限制了电池的循环寿命,是这种新型电池走向产品化的重要瓶颈。构建（002）晶面择优取向的锌负极被认为是抑制枝晶生长、提升电极库仑效率的有效手段。回溯近期有关金属锌负极的研究,本文首先概述了金属锌的电极过程和沉积形貌的影响因素,基于此从基底设计、涂层设计、电解液设计三个方面,着重总结了（002）晶面择优取向锌负极的设计策略和作用原理,最后展望了（002）晶面择优取向金属锌负极面临的挑战和未来发展方向,特别指出应在面向实用化锌离子电池的条件下评估金属锌负极的电化学性能和改性效果。     

锂离子电池负极材料钛酸锌锂的研究进展

报道了钛酸锌锂材料研究现状。对钛酸锌锂的结构与性能、合成方法和改性方法进行阐述。最后对钛酸锌锂负极材料进行总结和展望。     

改性生物质炭/缓释氧剂复合材料的制备及其性能研究

将生物质炭、过氧化钙和有机生物絮凝剂联合改性、吸附结合研制出改性生物质炭/缓释氧剂复合材料,对其进行表征分析,并结合pH、氧化还原电位指标确定去除水体、底泥中重金属镉、砷效果最佳配比的复合材料。结果表明,不同比例制备的复合材料对水体中5 mg/L镉、10 mg/L砷去除率均接近100%,符合地表水水质标准,pH由9.5降至7.0,Eh维持在中度还原状态。此外,当改性生物质炭(BC_(Fe))∶缓释氧剂(BF_(CP))为15∶1质量比时,对于水体镉、砷的去除效果较佳;而当BC_(Fe)∶BF_(CP)为15∶5和15∶1时制备的复合材料稳定化底泥中镉、砷效果较佳,pH处于中性,Eh低于200 mV。     

纳米改性碳/酚醛树脂基复合材料性能研究

针对碳/酚醛树脂基复合材料层间剪切强度低的缺点,采用纳米填料进行改性。测试了2种纳米填料(纳米碳纤维、碳纳米管)改性后酚醛树脂的热解性能,研究了纳米填料对复合材料力学性能、烧蚀性能以及高温炭化后力学性能的影响,并观察分析了复合材料测试后的微观形貌。研究结果表明,纳米填料改性后,复合材料的力学性能、烧蚀性能均有所改善。其中,纳米碳纤维改性后复合材料的常温层间剪切强度达到24.9 MPa,氧乙炔线烧蚀率为22.75μm/s,质量烧蚀率为23.58 mg/s。纳米碳纤维表面粗糙,与树脂基体的界面强度高,因此其改性后的力学性能和烧蚀性能优于碳纳米管。     

改性活性炭/碳纳米管复合电极脱盐性能研究

采用改性CNT*作为CDI电极导电剂,制备AC*/CNT*复合电极,考察其脱盐性能。利用BET、FTIR和TEM对AC或CNT的表面结构、官能团种类和分散性进行分析。利用电化学工作站和SEM对复合电极的比电容、阻抗和表面形貌进行分析。结果表明,通过改性,AC*的比表面积达到672.48 m2/g,增加了29.43%;CNT*的比表面积为117.39 m2/g,下降了9.94%,但其分散性得到有效改善。根据循环伏安测试和静态脱盐实验结果 ,按AC*∶CNT*∶PVDF=7.2∶0.8∶2质量比制备的电极效果最好,比电容高达130.48 F/g,比吸附量达到7.29 mg/g。     

Effects of electrolytes on the electrochemical performance of Si/graphite/disordered carbon composite anode for lithium-ion batteries

The influences of LiBF₄, LiClO₄, lithium bis(oxalato) borate (LiBOB), LiPF₆ with VC and without VC, and the mixed electrolytes composed of different ratios of LiBOB and LiPF₆ or LiClO₄ on the electrochemical properties of Si/graphite/disordered carbon (Si/G/DC) composite electrode were systematically investigated by constant current charge-discharge and electrochemical impedance spectra (EIS) techniques. Scanning electron microscopy (SEM) was used to observe the change of electrodes in morphology after given cycle numbers. X-ray photoelectron spectroscopy (XPS) was employed to understand the influences of different mixed electrolytes on the composition of SEI layers. The results showed that Si/G/DC composite electrode in the mixed electrolytes presented better electrochemical performance than in single electrolyte. The compactness and compositions of SEI layers intensively influenced the cycle performance of Si/G/DC composite materials. LiBOB and additive VC had a good synergistic effect on the formation of the dense SEI layers. In particular, Si/G/DC in 0.5 M LiBOB + 0.38 M LiPF₆ electrolytes containing VC exhibited a high reversible capacity and excellent cycle performance.     

Study on performance of composite polymer films doped with modified molecular sieve for lithium-ion batteries

To improve the tensile strength and ionic conductivity of composite polymer films for lithium-ion batteries, molecular sieves of MCM-41 modified with sulfated zirconia (SO₄²⁻/ZrO₂, SZ), denoted as MCM-41/SZ, were doped into a poly(vinylidene fluoride) (PVdF) matrix to fabricate MCM-41/SZ composite polymer films, denoted as MCM-41/SZ films. Examination by transmission electron microscope (TEM) shows that modified molecular sieves have lower aggregation and a more porous structure. Tensile strength tests were carried out to investigate the mechanical performance of MCM-41/SZ films, and then the electrochemical performance of batteries with MCM-41/SZ films as separators was tested. The results show that the tensile strength (σ_t) of MCM-41/SZ film was up to 7.8 MPa; the ionic conductivity of MCM-41/SZ film was close to 10⁻³ S cm⁻¹ at room temperature; and the coulombic efficiency of the assembled lithium-ion battery was 92% at the first cycle and reached as high as 99.99% after the 20th cycle. Meanwhile, the charge-discharge voltage plateau of the lithium-ion battery presented a stable state. Therefore, MCM-41/SZ films are a good choice as separators for lithium-ion batteries due to their high tensile strength and ionic conductivity.     

Effects of heteroatoms on electrochemical performance of electrode materials for lithium ion batteries

Recent studies of lithium ion batteries focus on improving electrochemical performance of electrode materials and/or lowering cost. Doping of active materials with heteroatoms is one promising method. This paper reviews the effects of heteroatoms on anode materials such as carbon- and tin-based materials, and cathode materials such as LiCoO₂, LiNiO₂, LiMn₂O₄ and V₂O₅. There are favorable and unfavorable effects, which depend on the species and physicochemical states of heteroatoms and the parent electrode materials. In the application of lithium ion batteries advantageous factors should be exploited, unwelcome side effects should be avoided as far as possible. Considerable gains towards improved electrochemical performance of the electrode materials have been achieved. Nevertheless, there are still problems needing further investigation including theoretical aspects, which will in the meanwhile stimulate the investigation for better electrode materials.     

Hard carbon/lithium composite anode materials for Li-ion batteries

Hard carbon/lithium composite anode electrode is prepared to reduce the initial irreversible capacity of hard carbon, which hinders practical application of hard carbon in lithium ion batteries, by introducing lithium into hard carbon. Lithium foil effectively compensates the irreversible capacity of hard carbon in the first cycle. A full cell using LiCoO₂ cathode and the composite anode shows much higher initial coulombic efficiency than that of a cell using LiCoO₂ cathode and hard carbon anode. This paves the way to reduce the large initial irreversible capacity of hard carbon. Besides that, this composite anode enables conductive polymer/sulfur composite cathode to be used in Li-ion batteries with non-lithiated anode materials.     

有机-无机混成材料改性聚氨酯性能研究

研究了以1-羟基聚丁二烯为基体的聚氨酯添加聚碳二亚胺(PCDI)和聚硅氧烷(PSi)改性为一种有机-无机混成材料.当分别添加5%的PSi及40%的PSi和聚甲基苯基硅氧烷(PMPS)所制得的绝热材质模数分别为33.4和90.0 MPa,伸长率分别为62%和16%;经热裂解后碳化层残留的质量分数增加0.7%～4%;升温速率与最大分解温度tm成线性关系,预计当燃料燃烧时升温速率为5 000 ℃/min时,在氮气下tm分别为538 ℃和522 ℃.所得改性材料具有较高的模数和热稳定性.     

On the electrochemical performance of anthracite-based graphite materials as anodes in lithium-ion batteries

The electrochemical performance as potential negative electrode in lithium-ion batteries of graphite materials that were prepared from two Spanish anthracites of different characteristics by heat treatment in the temperature interval 2400-2800 °C are investigated by galvanostatic cycling. The interlayer spacing, d₀₀₂, and crystallite sizes along the c axis, L_c, and the a axis, L_a, calculated from X-ray diffractometry (XRD) as well as the relative intensity of the Raman D-band, I_D/I_t, are used to assess the degree of structural order of the graphite materials. The galvanostatic cycling are carried out in the 2.1-0.003 V potential range at a constant current and C/10 rate during 50 cycles versus Li/Li⁺. Larger reversible lithium storage capacities are obtained from those anthracite-based graphite materials with higher structural order and crystal orientation. Reasonably good linear correlations were attained between the electrode reversible charge and the materials XRD and Raman crystal parameters. The graphite materials prepared show excellent cyclability as well as low irreversible charge; the reversible capacity being up to ∼250 mA h g⁻¹. From this study, the utilization of anthracite-based graphite materials as negative electrode in lithium-ion batteries appears feasible. Nevertheless, additional work should be done to improve the structural order of the graphite materials prepared and therefore, the reversible capacity.     

Improved electrochemical performance of silicon monoxide anode materials prompted by macroporous carbon

Journal of Porous Materials - Silicon monoxide (SiO) shows great potential for application as anode materials for lithium-ion batteries on account of its large capacity, low-cost, ample reserves...