Preparation and electrochemical properties of re-synthesized LiCoO2 from spent lithium-ion batteries

A new idea for reuse of the cathode materials of lithium-ion batteries(LIBs) is investigated to develop an environmentally friend-ly process for recycling spent batteries.LiCoO2 is re-synthesized from spent LIBs by leaching and a sol-gel method calcined at high temperature.Thermogravimetric analysis(TGA) and differential scanning calorimetry(DSC) are employed to study the re-actions occurring calcination that are responsible for the weight losses.X-ray diffraction(XRD) and scanning electron microscopy(SEM) are used to determine the structures of the LiCoO2 powders.It was found that a pure phase of LiCoO2 can be obtained by the re-synthesis process.Cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) are used to evaluate the electrochemical properties of the LiCoO2 powders.The discharge capacity of re-synthesized LiCoO2 is 137 mAh g-1 at the 0.1 C rate,and the capacity retention of the re-synthesized LiCoO2 is 97.98% after 20 cycles at the 0.1 C rate,and 88.14% after 40 cy-cles.The results indicate that the re-synthesized LiCoO2 displays good charge/discharge performance and cycling behavior.     

Sn/C复合材料的制备及作为锂离子电池负极材料的性能

采用SnCl2.2H2O乙醇溶液浸渍竹炭和NaBH4还原方法制备出一种锂二次电池负极用Sn/C复合材料。考察了复合材料中Sn含量对产物收率、微观结构及电化学性能的影响。结果表明,Sn2+大部分进入到竹炭的孔道中,并被还原为单质Sn;当单质Sn与复合材料质量比为42.5∶100时,复合电极材料具有555.1mAh/g的可逆容量,循环20次后容量保持在423.8 mAh/g,显示出较好的实用性能。     

Effect of modified elastomeric binders on the electrochemical properties of silicon anodes for lithium-ion batteries

Silicon has been investigated intensively as a promising anode material for rechargeable lithium-ion batteries. The choice of a binder is very important to solve the problem of the large capacity fade observed along cycling. The effect of modified elastomeric binders on the electrochemical performance of crystalline nano-silicon powders was studied. Compared with the conventional binder (polyvinylidene fluoride (PVDF)), Si electrodes using the elastomeric styrene butadiene rubber (SBR) and sodium carboxymethyl cellulose (SCMC) combined binder show an improved cycling performance. The reversible capacity of the Si electrode with the SCMC/SBR binder is as high as 2221 mA·h/g for 30 cycles in a voltage window between 0.005 and 2 V. The structure changes from SEM images of the silicon electrodes with different binders were used to explore the property improvement.     

锂离子电池LiFePO4/Li3V2(PO4)3复合正极材料的制备及性能研究

为了提高LiFePO₄正极材料的离子导电性,采用液相共沉淀法与碳热还原法制备一系列质量配比的LiFePO₄/Li₃V₂(PO₄)₃复合材料,通过X-射线衍射、扫描电镜、恒流充放电测试仪等分析测试手段测试样品。研究发现,m(LiFePO₄):m(Li₃V₂(PO₄)₃)=6:4时复合材料形貌较为规则且结晶度较高,在0.1C,1.0C,2.0C,5.0C,10.0C倍率下放电比容量可达148,136,130.5 ,121.5,112.3 mA·h·g-1,1C倍率下循环100次容量保持率仍可达98.5%,有效地解决了LiFePO₄离子电导率低的问题,推动了该复合正极材料在动力型锂离子电池中的应用。     

锂离子电池LiFePO4/Li3 V2(PO4)3复合正极材料的制备及性能研究

为了提高LiFePO₄正极材料的离子导电性,采用液相共沉淀法与碳热还原法制备一系列质量配比的LiFePO₄/Li₃V₂(PO₄)₃复合材料,通过X-射线衍射、扫描电镜、恒流充放电测试仪等分析测试手段测试样品。研究发现,m(LiFePO₄):m(Li₃V₂(PO₄)₃)=6:4时复合材料形貌较为规则且结晶度较高,在0.1C,1.0C,2.0C,5.0C,10.0C倍率下放电比容量可达148,136,130.5 ,121.5,112.3 mA·h·g-1,1C倍率下循环100次容量保持率仍可达98.5%,有效地解决了LiFePO₄离子电导率低的问题,推动了该复合正极材料在动力型锂离子电池中的应用。     

Electrochemical properties of CoFe3Sb12 as potential anode material for lithium-ion batteries

A skutterudite-related antimonide, CoFe3Sb12,was prepared with vacuum melting.XRD analysis showed the material contained Sb, FeSb2, CoSb2 and CoSb3 phases.The electrochemical properties of the ball-milled CoFe3Sb12-10wt% graphite composite were studied using pure lithium as the reference electrode. A maximal lithium inserting capacity of about 860 mAh/g was obtained in the first cycle.The reversible capacity of the material was about 560mAh/g in the first cycle and decreased to ca.320 mAh/g and 250 mAh/g after 10 and 20 cycles respectively.Ex-situ XRD analyses showed that the antimonides in the pristine material were decomposed after the first discharge and that antimony was the active element for lithium to insert into the host material.     

Nanostructured LiMn2O4 and their composites as high-performance cathodes for lithium-ion batteries

Improvement of the energy density and power density of the lithium-ion batteries is urgently required with the rapid development of electric vehicles and portable electronic devices. The spinel LiMn2O4 is one of the most promising cathode materials due to its low cost, nontoxicity, and improved safety compared with commercial LiCoO2. Developing nanostructured electrode materials represents one of the most attractive strategies to dramatically enhance battery performance, such as capacity, rate capability and cycling life. Currently, extensive efforts have been devoted to developing nanostructured LiMn2O4 and LiMn2O4/carbon nanocomposites to further improve the rate capability of lithium-ion batteries for high-power applications. In this paper, recent progress in developing nanostructured LiMn2O4 and LiMn2O4/carbon nanocomposites is reviewed, and the benefits to the electrochemical performance of LiMn2O4-based cathodes by using these electrode materials are also discussed.     

锂离子电池正极材料LiNi0.45Co0.10Mn0.45O2的合成及电化学性能

以Li2CO3 和Ni-Co-Mn 三元系氧化物为原料,在空气中通过固相反应制备LiNi0.45Co0.10Mn0.45O2.研究反应条件对产物结构的影响,采用扫描电镜(SEM)表征样品的形貌,用粒度分析、振实密度和比表面测定等手段比较不同合成条件对产物性能的影响.研究结果表明当n(Li)/n(M)不同时合成的产物性能差别很大,较适宜的n(Li)/n(M)为1.4/1;球磨可以提高产物的振实密度和比表面,并且对改善材料电化学性能有显著影响,在2.75～4.25 V电压范围内LiNi0.45Co0.10Mn0.45O2 首次放电比容量达到125.9 mA·h/g,50 次循环后放电比容量为128.7 mA·h/g.     

Comparative study of LiNiO2, LiNi0.8Co0.2O2 and LiNi0.75Al0.25O2 for lithium-ion batteries

The comparative study of LiNi0.8Co0.2O2 and LiNi0.75Al0.25O2 was carried out by X-ray diffraction (XRD) and electrochemical methods. The results show that Co and Al doping suppress the phase transition during charge-discharge. The experiments indicate that LiNi0.75Al0.25O2 has the better cycle-ability and over-charge resistance comparing with LiNi0.8Co0.2O2. The interfacial behavior was studied by use of electrochemical impedance spectroscopy (EIS). The results show that LiNi0.75Al0.25O2 has a slightly larger polarization character than LiNi0.8Co0.2O2.     

锂在锂离子电池石墨电极中电化学嵌脱层的可逆性

对石墨化热处理温度与其充放电性能的关系以及锂在石墨负极中不能可逆嵌脱的原因进行了研究．在不同的最高热处理温度(t     

A facile method to synthesize 3D structured Sn anode material with excellent electrochemical performance for lithium-ion batteries

Sn anode materials with high specific capacity are an appealing alternative to graphite for next-generation advanced lithium-ion batteries. However, poor electrochemical performance originating from fracture and pulverization due to the enormous volume changes during lithium alloying/dealloying hinders their commercial applications. Here, we propose the synthesis of a novel 3D structured Sn anode material by a facile method: heat treatment of nanosized SnO₂ spheres in a tube furnace w...     

锂离子电池正极材料Li2FeSiO4的改性

采用高温固相反应法在氩气气氛下合成锂离子电池正极材料Li2FeSiO4、Li2FeSiO4/C和Li2Fe0.9Mn0.1SiO4/C,并采用X线衍射、扫描电镜和电化学方法研究材料的结构与性能.研究结果表明:改性后的Li2FeSiO4/C和Li2Fe0.9Mn0.1SiO4/C材料与Li2FeSiO4具有相同的晶体结构,锰离子掺杂和表面碳包覆有效地提高了材料的比容量和循环性能.以C/16倍率充放电,Li2FeSiO4/C的首次放电容量为112mA·h/g,Li2Fe0.9Mn0.1SiO4/C材料首次放电容量达122 mA·h/g,充放电循环30次后容量衰减仅为9％.     

MnO@CoMn$_{textbf{2}}$O$_{textbf{4}}$/N-C纳米线复合材料的制备及其作为锂离子电池阳极材料的电化学性能

过渡金属氧化物作为锂离子电池(lithium-ion batteries, LIBs)阳极材料时具有较高的理论容量, 但因其电导率低, 以及充放电过程中的体积膨胀效应常会导致容量的快速衰减. 碳包覆是提升金属氧化物导电性的有效方法, 二者之间的协同效应也可以有效提升材料的电化学性能. 以MnO$_{2}$纳米线为模板制备出MnO$_{2}$@ZIF-67有机-无机杂化纳米结构, 再通过退火处理合成了氮掺杂碳包覆的MnO@CoMn$_{2}$O$_{4}$纳米线复合材料(MnO@CoMn$_{2}$O$_{4}$@N-C). ZIF-67的有机配体在高温煅烧过程中发生碳化反应, 产生了氮掺杂碳, 提升了导电性. 当作为锂离子电池阳极材料时, MnO@CoMn$_{2}$O$_{4}$/N-C纳米线复合材料在0.1 A/g电流密度下的首次放电比容量为1 594.6 mA$cdot$h/g, 并且在100次充放电循环后的放电比容量仍保持在 925.8 mA$cdot$h/g, 在0.5 A/g电流密度下经200次充放电循环后的放电比容量仍维持在837.6 mA$cdot$h/g, 同时具有优异的倍率循环性能. 这种优异的电化学储能特性主要来源于复合材料的特殊结构, 以及氮掺杂碳的包覆.     

废弃手机锂离子电池机械破碎的基础研究

对废弃手机锂离子电池的结构特点进行分析,并研究其抗压、抗拉、抗弯、抗剪、抗冲击破碎力学性能。选择以水为介质的湿法冲击式破碎机对其进行破碎研究。研究结果表明:废弃手机锂离子电池各组分的结合方式易于破碎解离,属韧而软的塑性材料;弯力、剪切力、冲击力有利于实现锂离子电池的破碎;钴酸锂、碳素材料主要富集在粒度低于0.250 mm的破碎产物中,而塑料外壳、隔离膜、铜箔、铝箔等物质主要富集在粒度高于0.250 mm的破碎产物中;钴酸锂在粒度为0.075~0.125 mm的破碎产物中富集,其Co质量分数为36.58%;碳素材料在粒度为0.125~0.250 mm和低于0.075 mm这2种破碎产物中富集,其质量分数分别为73.39%和72.65%;湿法冲击破碎可以有效实现废弃手机锂离子电池的选择性破碎。     

Practical development and challenges of garnet-structured Li7La3Zr2O12 electrolytes for all-solid-state lithium-ion batteries: A review

All-solid-state Li-ion batteries (ASSLIBs) have been widely studied to achieve Li-ion batteries (LIBs) with high safety and energy density. Recent reviews and experimental papers have focused on methods that improve the ionic conductivity, stabilize the electrochemical performance, and enhance the electrolyte/electrode interfacial compatibility of several solid-state electrolytes (SSEs), including oxides, sulf-ides, composite and gel electrolytes, and so on. Garnet-structured Li7La3Zr2O12 (LLZO) is highly regarded an SSE with excellent application potential. However, this type of electrolyte also possesses a number of disadvantages, such as low ionic conductivity, unstable cubic phase, and poor interfacial compatibility with anodes/cathodes. The benefits of LLZO have urged many researchers to explore effective solutions to over-come its inherent limitations. Herein, we review recent developments on garnet-structured LLZO and provide comprehensive insights to guide the development of garnet-structured LLZO-type electrolytes. We not only systematically and comprehensively discuss the preparation, ele-ment doping, structure, stability, and interfacial improvement of LLZOs but also provide future perspectives for these materials. This review expands the current understanding on advanced solid garnet electrolytes and provides meaningful guidance for the commercialization of ASSLIBs.     

从废旧锂离子电池中回收制备LiCoO_2

采用两步加热法法,通过正交实验对其在硝酸中溶解的回收工艺进行了优化,工艺参数为硝酸浓度1 mol/L,溶解时间1 h,加热温度75℃,质量浓度5 g/L,过氧化氢与硝酸体积比为0.16,并再次合成了钴酸锂.在溶解后的滤液中加入氨水、氢氧化锂,使锂和钴在滤液中的比保持在1.1,过滤烘干煅烧后获取L iCoO2黑色粉末.     

Sb$_{\mathbf 2}$O$_{\mathbf 3}$/Sb 锂离子电池负极材料的制备及电化学性能

以多孔锑 (Sb) 为原料利用微氧化法制备了三氧化二锑/锑 (Sb$_{2}$O$_{3}$/Sb) 复合材料. 首先通过梯度试验确定微氧化温度, 接着通过控制微氧化时长来控制产物中 Sb$_{2}$O$_{3}$ 的含量. 在制备的 Sb$_{2}$O$_{3}$/Sb 复合材料中, Sb 能改善复合物的电子传输能力从而提升倍率性能. Sb$_{2}$O$_{3}$ 提供高容量, 且基于转化反应生成的 Li$_{2}$O 能阻止锑金属的团聚, 提高复合物的循环稳定性. 由于这种协同效应, Sb$_{2}$O$_{3}$/Sb 复合材料在电流密度为 200 mA$\cdot$g$^{-1}$ 时的首次库仑效率为 78.2%, 经过 100 圈循环后容量高达 729.6 mAh$\cdot$g$^{-1}$, 而当电流密度为 10 000 mA$\cdot$g$^{-1}$ 时, 容量仍保持为 203 mAh$\cdot$g$^{-1}$. 对比多孔锑, Sb$_{2}$O$_{3}$/Sb 复合材料的循环和倍率性能均有显著提高.     

锂离子电池正极材料Li1+xV3O8的制备及动力学研究

采用二次缩合溶胶-凝胶法制备锂离子电池正极材料Li1 xV3O8,首次放电容量达330 mA.h/g,循环15次后容量衰减7.6%。测试不同温度下放电时正极材料Li1 xV3O8中Li 的扩散系数DLi ;从动力学角度研究了温度放电倍率密度对电池性能的影响。结果表明,随着温度的增加,DLi 增大,比容量相应增大;当以0.02 C的放电倍率放电时,电容量较高,以0.08 C的放电倍率放电时,电容量衰减约50%。