Urgent needs for second life using and recycling design of wasted electric vehicles (EVs) lithium-ion battery: a scientometric analysis.

Currently, lithium-ion batteries are increasingly widely used and generate waste due to the rapid development of the EV industry. Meanwhile, how to reuse "second life" and recycle "extracting of valuable metals" of these wasted EVBs has been a hot research topic. The 4810 relevant articles from SCI and SSCI Scopus databases were obtained. Scientometric analysis about second life using and recycling methodologies of wasted EVBs was conducted by VOSviewer, Pajek, and Netdraw. According to analytical results, the research of second life using and recycling mythologies has been growing and the expected achievement will continue to increase. China, Germany, the USA, Italy, and the UK are the most active countries in this field. Tsinghua University in China, "Fraunhofer ISI, Karlsruhe" in Germany, and "Polytechnic di Torino" in Italy are the most productive single and collaborative institutions. The journals SAE technical papers and World Electric Vehicle Journal have the highest publication and citations than other journals. Chinese author "Li Y" has the highest number of 36 publications, and his papers were cited 589 times by other authors. By analyzing the co-occurrence and keywords, energy analysis, second life (stationary using, small industry), and treatment methods, (hydrometallurgy and pyrometallurgical, electrochemical, bio-metallurgical) were the hot research topics. The S-curve from the article indicates hydrometallurgical and bio-metallurgical methods are attached with great potential in the near future. Further, different treatment methodologies are observed especially advanced techniques in hydrometallurgical, and spent medium bioleaching techniques in bio-metallurgical are good, economically cheap, has low CO 2 emission, environmentally friendly, and has high recovery rate. Finally, this research provides information on second life use and top recycling methodology opportunities for future research direction for researchers and decision-makers who are interested in this research.