High-performance Ni-Co-Mn electrocatalyst recovered from spent lithium-ion battery cathode materials for robust oxygen evolution in acid solution  

从废旧锂离子电池正极材料中回收用于酸性电解液析氧反应的Ni-Co-Mn电催化剂

作　　者：JIANG Liang-xing FAN Yao-jian LIU Fang-yang ZHANG Zong-liang WANG Jun 蒋良兴;樊瑶建;刘芳洋;张宗良;王君(School of Metallurgy and Environment,Central South University,Changsha 410083,China;School of Chemistry and Chemical Engineering,Changsha University of Science and Technology,Changsha 410114,China;National Energy Metal Resources and New Materials Key Laboratory,Changsha 410083,China)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]School of Chemistry and Chemical Engineering,Changsha University of Science and Technology,Changsha 410114,China [3]National Energy Metal Resources and New Materials Key Laboratory,Changsha 410083,China

出　　处：《Journal of Central South University》2024年第12期4472-4482,共11页中南大学学报(英文版)

基　　金：Project(2022YFC3900804)supported by the National Key Research and Development Program,China;Projects(2021JJ10058,2022JJ10074)supported by the Natural Science Foundation of Hunan Province of China。

摘　　要：Recovering valuable metals from spent lithium-ion batteries(LIBs)for high value-added application is beneficial for global energy cycling and environmental protection.In this work,we obtain the high-performance N-doped Ni-Co-Mn(N-NCM)electrocatalyst from waste LIBs,for robust oxygen evolution application.Lithium-rich solution and NCM oxides are effectively separated from ternary cathode materials by sulfation roasting and low-temperature water leaching approach,in which the recovery efficiency of Li metal reaches nearly 100%.By facile NH_(3)treatment,the incorporation of N into NCM significantly increases the ratio of low-valence state Co^(2+)and Mn^(2+),and the formed Mn-N bond benefits the surface catalytic kinetics.Meanwhile,the N doping induces lattice expansion of the NCM,triggering tensile stress to favor the adsorption of the reactant.Thus,the optimized N-NCM electrocatalyst exhibits the superior overpotentials of 256 and 453 mV to achieve the current density of 10 and 100 mA/cm^(2),respectively,with a low Tafel slope of 37.3 mV/dec.This work provides a fresh avenue for recycling spent LIBs in the future to achieve sustainable development.从废旧锂离子电池(LIBs)中回收有价值的金属,有利于全球能源循环和环境保护。本文通过硫酸化焙烧和低温水浸法,从三元正极材料中有效分离出了富Li溶液和Ni-Co-Mn三元氧化物(NCM),其中溶液中金属Li的回收率接近100%。NCM在450℃下进行NH_(3)处理后成功将N掺入其晶格中,在XPS结果中可明显观察到低价态Co^(2+)和Mn^(2+)的比例增大,而伴随Mn-N键的形成有利于电极表面电催化的反应动力学。同时,通过TEM可明显观察到N掺杂会引起NCM的晶格膨胀,引发拉伸应力,这些变化有利于电极表面对反应物的吸附。因此,优化后的N-NCM电催化剂在电流密度为10和100 mA/cm^(2)时(电解液为0.5 mol/L H_(2)SO_(4)),析氧反应的过电位分别仅为256和453 mV,塔菲尔斜率低至37.3 mV/dec。该研究为未来回收利用LIBs以实现可持续发展提供了一条新途径。

关 键 词：recovered Ni-Co-Mn oxides N doping oxygen evolution electrocatalyst spent ternary lithium-ion batteries 

分 类 号：O64[理学—物理化学]