Yao Ning, Liu Fu, Shao Ahu, Xue Rongrong, Jia Qiurong, Liu Yuyao, Wang Helin, Wang Xin, Zhang Yaxin, Zhang Min, Wang Zhiqiao, Li Yunsong, Tang Jiawen, Tang Xiaoyu, Ma Yue
State Key Laboratory of Solidification Processing, Centre for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China.
Department of Chemistry, City University of Hong Kong, Hong Kong, 999077, China.
Adv Mater. 2024 Nov;36(46):e2408268. doi: 10.1002/adma.202408268. Epub 2024 Sep 27.
The substantial manufacturing of lithium-ion batteries (LIBs) requires sustainable, circular, and decarbonized recycling strategies. While efforts are concentrated on extracting valuable metals from cathodes using intricate chemical process, the direct, efficient cathode regeneration remains a technological challenge. More urgently, the battery supply chain also requires the value-added exploitation of retired anodes. Here, a "closed-loop" approach is proposed to upcycle spent graphite into the prelithiation catalyst, namely the fewer-layer graphene flakes (FGF), upon the exquisite tuning of interlayer spacing and defect concentration. Since the catalytic FGF mitigates the delithiation energy barrier from calcinated LiFeO nanocrystalline, the composite layer of which cast on the polyolefin substrate thus enables a customized prelithiation capability (98% Li utilization) for the retired LiFePO recovery. Furthermore, the hydrophobic polymeric modification guarantees the moisture tolerance of LiFeO agents, aligning with commercial battery manufacturing standards. The separator strategy well regulates the interfacial chemistry in the anode-free pouch cell (LiFePO||Cu), the prototype of which balances the robust cyclability, energy density up to 386.6 Wh kg as well as the extreme power output of 1159.8 W kg. This study not only fulfills the sustainable supply chain with graphite upcycling, but also establishes a generic, viable protocol for the anode-free cell prototyping.
锂离子电池（LIBs）的大规模生产需要可持续、循环和脱碳的回收策略。虽然人们致力于通过复杂的化学工艺从阴极中提取有价值的金属，但直接、高效的阴极再生仍然是一项技术挑战。更紧迫的是，电池供应链还需要对退役阳极进行增值利用。在此，提出了一种“闭环”方法，通过对层间距和缺陷浓度进行精细调控，将废旧石墨升级为预锂化催化剂，即少层石墨烯薄片（FGF）。由于催化性FGF降低了煅烧LiFeO纳米晶体的脱锂能垒，因此浇铸在聚烯烃基材上的其复合层能够为回收的LiFePO提供定制的预锂化能力（锂利用率达98%）。此外，疏水性聚合物改性确保了LiFeO试剂的防潮性，符合商业电池制造标准。该隔膜策略很好地调节了无阳极软包电池（LiFePO||Cu）中的界面化学，其原型兼具稳健的循环稳定性、高达386.6 Wh kg的能量密度以及1159.8 W kg的极限功率输出。本研究不仅通过石墨升级实现了可持续供应链，还为无阳极电池原型设计建立了一个通用、可行的方案。
