Fabrication of Silicon/Carbon Composite Material with Silicon Waste and Carbon Nanofiber Applied in Lithium-Ion Battery

Silicon (Si) is regarded as a promising material for lithium-ion battery anode because of high theoretical capacity. Nevertheless, Si faces particle pulverization and rapid capacity fading due to serious volume change during the lithiation and the delithiation process. In this work, a silicon/carbon composite constituted to Si powder and carbon nanofiber (CNF) is produced to solve the above issues as a new design structure of anode material. The Si powder was recycled from the silicon slicing waste in photovoltaic industry and the CNF was from dry rice straws. By mixing the purified Si powder with CNF, the composite was synthesized by the freeze-drying method and calcination. In the cyclic test, Si adding with 1 wt% CNF showed 3091 mAh/g capacity in the first cycle and 1079 mAh/g capacity after 100 cycles at the current density of 0.5 A/g, which were both better than pristine Si. SEM images also show the composite structure can eliminate cracks on the surface of the electrode during cycling. CNF attaching on Si particles can increase specific surface area, so binder can easily combine the active materials and the conductive materials together. This strategy enhances the structure stability and prevents the electrode from delamination.

废锂离子电池碳热还原优先提锂工艺优化

对废旧三元锂离子电池正极材料采用碳热还原-通二氧化碳水浸的工艺进行优先提锂。本文采用单一变量法探究焙烧过程中焙烧温度、焙烧时长、有效加碳量及水浸过程中水浸时长、水浸固液比、二氧化碳流量、逆流水洗级数等参数改变带来的金属元素浸出率的影响。在焙烧温度700℃、焙烧时长120min、有效加碳量(75.56%含碳量的炭粉)为14%(质量分数)、液固比10mL/g、水浸时长180min、二氧化碳通入量100mL/min、三级逆流水洗的最佳条件下,可以达到锂的浸出率为96.31%,钴、镍、锰金属的浸出率均低于0.1%。同时考察了该工艺对于不同型号的废三元锂离子电池回收的适用性,发现提锂效果均在90%以上,具有良好的原料适应性。此外,通过X射线衍射、透射电子显微镜、扫描电子显微镜探究碳热还原前后的物相变化。

铜冶炼酸性废水浸出废旧三元锂离子电池正极材料中Co的动力学研究

采用铜冶炼酸性废水浸出废旧三元锂离子电池正极材料,考察了浸出温度、酸性废水中初始H_(2)SO_(4)浓度、搅拌速度对Co浸出率的影响。结果表明,当浸出时间150 min、浸出温度363 K、液固比12.5、还原剂淀粉用量10 g L、酸性废水中初始H_(2)SO_(4)浓度1.5 mol L时,正极材料中Co的浸出率可达99.12%。利用未反应收缩核模型分析了还原浸出过程中Co的动力学。结果表明,Co的浸出过程受内扩散和界面化学反应混合控制,表观活化能为23.657 kJ mol,动力学方程为:1-(1-x)^(1/3)+β[1-2/3x-(1-x)^(2/3)]=4.5243C^(1.29211)V^(1.60337)[exp(RT/23657)]t。

Scalable synthesis of N-doped Si/G@voids@C with porous structures for high-performance anode of lithium-ion batteries

The co-utilization of silicon(Si) and graphite(G) has been considered as the preferred strategy to achieve high energy density anode materials,but the effective synergistic integration of Si and graphite is still a challenge and it is necessary to find a scheme to accommodate the large-scale production of Si/graphite anodes.In this work,silicon cutting waste from the photovoltaic industry was used as raw material,mixed with graphite,pitch,and polyvinylpyrrolidone,and subjected to high-energy ball milling.The mixture was then heated in an Ar atmosphere for the carbon coating,and the resulting Si/graphite/carbon(Si/G/C) composite was etched to remove the thicker SiOx layer formed on the Si surface to allow the pores between the Si and the carbon matrix to obtain Si@voids/G@C.Benefiting from the integrated structural design and the significantly enhanced electronic conductivity,the Si/G@voids@C composite exhibited the first dischargespecific capacity of 2530 mAh·g^(-1) with an initial coulombic efficiency(ICE) of 86.7%,and the remaining capacity exceeded 1000 mAh·g^(-1) after 550 cycles at 1.5A·g^(-1).Notably,full lithium-ion batteries with a Si/G@voids@C anode and LiFePO_4 cathode delivered a stable capacity of 140 mAh·g^(-1).The synthesis method is facile and cost-effective,providing an integration strategy for Si and G with a potential scheme for large-scale commercial applications.

Current Trends in Sourcing, Recycling, and Regeneration of Spent Lithium-Ion Batteries—A Review

The demand for lithium-ion batteries(LIBs)has been increasing exponentially due to their applications in portable electronics and electric vehicles.Consequently,the raw materials required to manufacture LIBs,including geopolitically scarce metals such as lithium and cobalt,have also witnessed a surge in demand.Moreover,the accumulation of spent LIB also raises safety and waste management concerns.Because reducing fossil fuel dependency is an integral part of energy transitions,this trend is expected to continue,which introduces numerous challenges.The primary challenge is the potential for the demand of raw materials required in LIB production to outpace supply along with the environmental,technical,and ethical constraints associated with the primary extraction of raw materials like lithium.This work examines the importance of LIBs in upcoming energy transitions and the environmental impact of its burgeoning demand.A summary of the current trends and techniques employed in LIB recycling and regeneration as well as the limitations of these methods are also explored.The review provides a comprehensive overview on LIB recycling in keeping with the principles of a circular economy by uniting the technical,environmental,economic,and political aspects of spent battery management.

Potential use of magnesium industrial waste for synthesis of Li and Mg co-doped LiMn_(2)O_(4)nanoparticles as cathode material for Li-ion batteries:Effect of sintering temperature

Potential advantages of active electrode nanomaterials have led to development of high energy and power density lithium-ion(Li-ion)batteries.However,under increasing demand for critical resources such as lithium and cobalt,it is necessary to use abundant raw materials,which can be obtained from industrial waste.In this work,purified Mg(OH)_(2)from waste generated in the production of Li2CO3 with natural brines from the Salar de Atacama(Chile)is used as a doping agent for synthesis of LiMn_(2)O_(4)(LMO)spinel octahedral nanoparticles co-doped with excess Li and Mg.Crystallization of a pure cubic spinel phase(Fd3m)takes place at 500℃and sintering temperature effect at 580 and 750℃,thus the elemental composition and the structural,morphological,and electrochemical properties are studied in detail.Optimum electrochemical performance at room temperature is obtained for Li_(1.03)Mg_(0.05)Mn_(1.92)O_(4)spinel sintered at 750℃with an initial discharge capacity of 121.3 mAh·g^(-1)and capacity retention of 94.0%after 100 cycles at C/3.A locally ordered spinel structure is obtained at 750℃,and doping with Mg^(2+)improves structural rigidity.Synergy between both effects resulted in a high Li^(+)diffusion rate(1.29×10^(-9)cm^(2)·s^(-1))significantly improving cycling performance at elevated C-rates in 50℃.

废旧锂电池的机械化学法回收与再制备研究

采用机械活化回收废旧锂电池正极材料钴酸锂(LiCoO2)中的有价金属钴,实现常温环境中有价金属的高效浸出,并进一步以浸出液为原料,采用水热沉淀法制备镍钴锰酸锂(NCM622)三元正极材料。研究浸出条件对LiCoO2中钴浸出率的影响,以及制备NCM622正极材料时过渡金属与尿素物质的量比对其电化学性能的影响。实验结果表明:在球磨时间为75 min、球磨转速为400 r/min、固液比为1∶50、球料比为35∶1条件下,钴的浸出率达到96.44%;在过渡金属与尿素物质的量比为1∶3的条件下,制备的NCM622正极材料具有良好的α-NaFeO_(2)层状结构,Ni、Co、Mn的原子比基本符合6∶2∶2,且其电化学性能良好,首圈放电比容量为154.4 mAh/g,30圈循环后容量保持率为96.11%。

微波辅助回收废旧三元锂电池中的有价金属

以抗坏血酸和葡萄糖酸混合酸为浸出体系,辅以微波加热技术从废旧三元锂电池正极材料中浸出有价金属。采用N-N,二甲基吡咯烷酮(NMP)对废旧三元锂电池正极材料进行预处理。单因素试验确定的最佳条件为:微波温度90℃、微波反应时间6 min、抗坏血酸浓度0.5 mol/L、葡萄糖酸浓度1 mol/L、固液比20 g/L,获得对应Mn、Co、Ni、Li的浸出率分别是99.5%、98.7%、99.7%、97.8%。与传统浸出法相比较,微波辅助浸出效率更高。

废旧三元锂电池正极材料的回收与再利用

以废旧三元锂电池正极材料为研究对象,采用碳热还原—水浸—高温固相焙烧流程实现选择性回收Li和Ni、Co、Mn再利用的闭环回收工艺。在焙烧温度650℃、焙烧时间2 h、碳添加量10%、浸出时间1 h、固液比30 g/L的最佳条件下,Li浸出率为91.04%,浸出液循环浸出三次,可将浸出液Li浓度从1.01 g/L提高至2.68 g/L。浸出液蒸发结晶制备Li2CO_(3),主要成分为Ni、Co、MnO的浸出渣在空气氛围下焙烧制备三元前驱体,再将Li2CO_(3)和三元前驱体混合研磨进行焙烧,获得再生三元材料。

废旧电池制备Al掺杂三元锂离子电池正极材料的研究

以废旧锂离子电池正极材料溶解液为原料,调节镍、钴和锰离子配比,通过共沉淀法制备LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)前驱体,通过高温固相合成法掺杂Al制备锂离子电池正极材料.并利用XRD、SEM和电池性能测试系统对制备材料进行表征和电性能分析.结果表明:当煅烧时间为12 h、煅烧温度为900℃、掺杂Al_(2)O_(3)的质量分数为0.66%时,所制备正极材料首次充电比容量和首次充放电效率分别为141.7 m Ah/g和96.1%,样品层状结构良好,晶体排布规则.颗粒均匀,无团聚现象.掺杂Al可以有效改善LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)电池中Ni^(2+)和Li^(+)混排问题,提高正极材料的电性能和循环性能.

废旧三元锂离子电池正极材料资源化技术研究进展

随着现代化工业发展,锂离子电池在新能源领域中发挥着举足轻重的作用,废旧三元锂离子电池产量呈现出急剧增长的态势。在不影响生态平衡和人类健康的前提下,以资源化回收废旧锂电池将是我们面临的重要挑战。本文综合阐述了湿法、火法收、火法-湿法联用等回收废旧三元锂离子电池的常用方法,其中火法-湿法联用回收效率高、污染小、安全性高、经济成本较低,在工业化生产上具有很好的发展前景。

废旧三元锂离子电池回收技术研究新进展

随着锂离子电池产业的发展,三元锂离子电池废旧造成的环境污染和资源耗竭问题日益严重,大量废旧的锂电池,含有丰富的锂、镍、钴等高价元素,具有巨大的潜在资源和高昂的循环经济成本。随着锂离子电池数量的增加,废旧锂离子电池的资源回收无论从环境、医学还是经济的角度来看都是不可避免的,含三元锂的废锂电池材料再生技术开发体系,有助于防止废电池污染,缓解钴锂镍的压力,促进我国锂电池产业的良好发展。

硫酸化焙烧法回收废旧三元电池中锂的研究

针对废旧三元动力电池黑粉中锂回收传统方法存在回收工艺流程长、锂损失率高及纯度低的问题,提出了硫酸化焙烧法优先提锂的工艺。本文分析了硫酸化焙烧法提锂的热力学可行性,研究了不同硫酸盐、浓硫酸加入量、煅烧温度、煅烧时间对提锂效果的影响。不同硫酸盐的硫酸化焙烧实验结果表明,采用浓硫酸、硫酸氢钠、硫酸铵进行硫酸化焙烧,锂收率均为95%左右;加入硫酸氢钠得到的焙烧后料较硬;加入浓硫酸得到的焙烧后料蓬松,呈蜂窝煤状;而加入硫酸铵焙烧后料为粉料,易于破碎,但会产生氨气;加入等量硫酸钠焙烧基本得不到磷酸锂,因此综合考虑选择浓硫酸进行硫酸化焙烧。浓硫酸优先提锂的最佳条件为:浓硫酸加入量为理论量的105%,煅烧温度为600℃,煅烧时间为2 h。在此条件下,锂收率可高达95.2%,制备的碳酸锂和磷酸锂的杂质浓度低,纯度高。

用抗坏血酸+琥珀酸浸出废三元锂电池中的镍锂

研究了以抗坏血酸+琥珀酸为浸出体系从废三元锂电池中回收镍、锂,考察了琥珀酸加入量、浸出时间、浸出温度、抗坏血酸浓度对镍、锂浸出率的影响。结果表明:在固液质量体积比2 mg/1 mL、琥珀酸加入量4/1、抗坏血酸浓度为0.2 mol/L、浸出时间40 min、浸出温度80℃最佳浸出条件下,镍、锂浸出率分别为95.58%和97.57%。该有机酸体系浸出效果较好。

废旧三元动力电池资源化回收锂的工艺优化

针对废旧三元动力电池回收工艺流程长,锂回收率低,且大部分企业锂回收仅生产粗制碳酸锂、磷酸锂,产品附加值低的现状,采用浮选-还原焙烧碳化提锂工艺生产电池级碳酸锂。结果显示,在优化工艺指标和设备参数下,锂回收率大于90%;通过浮选除去大部分负极石墨,可有效地减小浸出设备和压滤设备规格,并缩短后续镍钴锰元素回收工艺流程,减少萃取过程中的酸耗和碱耗;碳化提锂溶液杂质含量低,经净化处理后可生产电池级碳酸锂,从而提高企业经济效益。

废旧动力电池回收工艺研究

随着新能源汽车的蓬勃发展,退役动力电池回收技术成为了研究热点.本文首先简述了国内外废旧动力电池回收所采用的主要工艺,分析废旧动力电池回收过程中主要技术环节的特点和问题,并提出废旧三元正极材料回收工艺新思路,进行废旧三元正极材料粉经过助剂焙烧、浸出、酸浸回收有价金属的试验.结果表明:助剂焙烧选择性提锂效果较佳,锂与其他有价金属高效分离.

废旧锂离子动力电池三元正极材料短流程回收再生研究

随着我国经济发展速度逐渐加快,电力驱动的需求也逐渐增多。在此情况下,锂离子电池属于最佳的应用选择,因此受到了大量行业的欢迎。然而,由于应用的规模快速扩大,废弃锂离子电池的处理需求也出现了大幅上涨的趋势。为了提高锂电池应用的绿色环保效果,并加强金属回收效率,应当针对废弃锂离子电池的三元正极材料进行回收,达到良好的应用目标,进一步加强整体利用效率。本文旨在分析废弃锂离子电池构成的基础上,深入研究废弃锂离子电池的相关回收流程,以供参考。

Ternary Metal–Organic Framework Derived 2D Fe_(2)O_(3)/Co_(3)O_(4)/NiO/NC Heterostructured Nanosheets for Super Lithium Storage

Fe_(2)O_(3)/Co_(3)O_(4)/NiO/NC nanosheets have been successfully prepared via a two-step annealing process of ternary metal coordination polymer. Attributing to the synergistic effects of the multiple metal oxides and the unique 2D nanosheet structure, the improved electrical conductivity and effective electron/ion transfer enables Fe_(2)O_(3)/Co_(3)O_(4)/NiO/NC electrode to exhibit excellent electrochemical properties with outstanding rate capacity and cycling stability. This work may pave the way to construct ternary metal oxide electrode material with an excellent electrochemical performance by introducing multiple metal oxides.

Self-template formation of porous yolk-shell structure Mo-doped NiCo2O4 toward enhanced lithium storage performance as anode material

Hollow ternary metal oxides have shown enormous potential in lithium-ion batteries(LIBs),which is ascribed to their complex chemical composition,abundant active defect sites,and the synergy effect be-tween metals.In this work,we synthesized Mo-doped NiCo_(2)O_(4) porous spheres with yolk-shell structure by using a simple self-templating method.Surprisingly,other than the yolk-shell structure we had ob-tained,the inner core of the yolk-shell was also porous,which could fully enhance the electrolyte infil-tration and promote the transmission of lithium ions(Li+)and electrons(e−).The diameter of the porous core in the yolk-shell sphere was about 530 nm,and the outer shell’s thickness was up to 110 nm.In addition,the unique pores in the core appeared in the diameter of about 85 nm.With this structure,the volume expansion of the anode could be well inhibited during charge/discharge.It exhibited prominent electrochemical performance with high reversible capacity(1338 mA h g^(−1) at 100 mA g^(−1)),satisfactory cycle life(1360 mA h g^(−1) after 200 cycles at 100 mA g^(−1)),and exceptional rate capability(820 mA h g^(−1) at 2000 mA g^(−1))as anode material in LIBs.

废旧三元锂电池正极材料的金属浸出

三元锂电池正极材料中含有大量锰及其他有价金属元素,具有极高的回收利用价值。采用马弗炉加热至530℃,恒温1 h,去除三元锂电池正极材料上的聚偏氟乙烯和乙炔黑。用1 mol·L^(-1)的稀硫酸与质量分数为30%的双氧水超声作用10 min将正极集流体洗涤干净。采用1 mol·L^(-1)的稀硫酸将铝箔洗涤并回收。将2部分洗涤液置于90℃条件下反应60 min后加入过二硫酸钾,继续反应120 min,制得α-MnO_2颗粒。结果表明,锰回收率达到99.5%,镍、钴和锂元素的浸出率分别可达99.8%、99.7%和99.8%。实现三元锂电池的正极材料中镍钴锂的浸出及锰的回收。