废弃锂电池集流体绿色高效剥离及有价金属短程回收的基础研究

The efficient recycling of valuable metals from spent lithium ion batteries in an eco-friendly manner may promise certain resource, environmental and economic benefits. And current efforts in this field are mainly focused on the typical hydrometallurgical leaching, selective separation from leaching liquor and preparation of electrode materials. While few interests are concentrated on the green and efficient peeling off current collector, the short-cut extraction of valuable metals and the synergetic separation and re-generation of metals and acid. Therefore, this proposal will be based on the metal recovery from spent lithium ion batteries and propose a process based on “the green and efficient peeling off current collector in supercritical fluid/ ionic liquid coupled system – short-cut recycling of Co in phosphoric acid medium - synergetic separation and re-generation of metals and acid from Li enriched solution”. The main contents include the exploration of influence factor, reaction mechanism and theoretical model during the peeling off Al foils to illustrate the rapid/efficient dissolving/ migration of binder from the cathodes, the confirmation of the influencing mechanism, reaction mechanism and theoretical model for the leaching/precipitating short-cut reaction of Co and the revelation of internal relationship and internal mechanism for the synergetic separation and re-generation of Li and phosphoric acid. This proposal will be expected to provide a scientific theory and technological basis for the green and efficient recycling of valuable metals from current collectors of spent lithium ion batteries.

高效环保地对大量废弃锂电池中有价金属资源化回收有望产生一定的资源、环境和经济效益。目前，相关研究主要集中于有价金属的湿法浸提、浸出液中有价金属选择性分离及电极材料的制备；而针对集流体绿色高效剥离、有价金属短程回收及酸再生循环利用方面的研究较少。本项目以废弃锂电池中有价金属分离与回收为目的，提出“超临界流体/离子液体耦合体系下集流体绿色高效剥离—磷酸体系下钴浸出/沉淀短程耦合反应回收—富锂浸出液中锂酸协同分离再生”的研究方案。主要内容包括：阐明正极粘结剂在耦合体系下快速有效降解/迁移实现铝箔与活性物质剥离的影响因素、理论模型和作用机制；明确磷酸体系下钴浸出/沉淀短程耦合反应的影响机制、反应规律及存在形态与转化关系；揭示富锂浸出液中锂和磷酸协同分离的相互联系及内在机制。本项目的研究有助于为废弃锂电池中有价金属的绿色高效分离与回收提供科学理论依据及技术基础。

高效环保地对大量废弃锂电池中有价金属资源化回收利用有望产生一定的资源、环境和经济效益。目前，相关研究主要集中于有价金属的湿法浸提、浸出液中有价金属选择性分离及电极材料的制备；而针对集流体绿色高效剥离、有价金属短程回收及酸再生循环利用方面的研究较少。本项目以废弃锂电池中有价金属分离与回收为目的，提出了“高级氧化体系下集流体绿色高效剥离—不同酸媒介下钴浸出/沉淀短程耦合反应回收—富锂浸出液中锂酸协同分离再生”的研究方案。主要研究内容包括：（1）阐明了正极粘结剂在高级氧化体系下快速有效降解/迁移实现铝箔与活性物质快速剥离的影响因素、理论模型和作用机制；（2）明确了磷酸和酒石酸体系下钴浸出/沉淀短程耦合反应的影响机制、反应规律及存在形态与转化关系；（3）揭示了富锂浸出液中锂和磷酸协同分离的相互联系及内在机制。通过本项目的实施，发表SCI论文9篇，其中通讯作者/第一作者SCI论文8篇，中文EI期刊1篇，核心期刊1篇，受邀撰写废旧锂电池回收方面专著1部（章节），申请发明专利5项；受邀参加国内学术会议9人次，其中口头报告8人次。本项目的研究有助于为废弃锂电池中有价金属的绿色高效分离与回收提供科学理论依据及技术基础。