Wang Wenyu, Wang Rui, Zhan Renming, Du Junmou, Chen Zihe, Feng Ruikang, Tan Yuchen, Hu Yang, Ou Yangtao, Yuan Yifei, Li Cheng, Xiao Yinguo, Sun Yongming
Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen 518055, China.
Nano Lett. 2023 Aug 23;23(16):7485-7492. doi: 10.1021/acs.nanolett.3c01991. Epub 2023 Jul 21.
The recycling of LiFePO from degraded lithium-ion batteries (LIBs) from electric vehicles (EVs) has gained significant attention due to resource, environment, and cost considerations. Through neutron diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy, we revealed continuous lithium loss during battery cycling, resulting in a Li-deficient state (LiFePO) and phase separation within individual particles, where olive-shaped FePO nanodomains (5-10 nm) were embedded in the LiFePO matrix. The preservation of the olive-shaped skeleton during Li loss and phase change enabled materials recovery. By chemical compensation for the lithium loss, we successfully restored the hybrid LiFePO/FePO structure to pure LiFePO, eliminating nanograin boundaries. The regenerated LiFePO (R-LiFePO) exhibited a high crystallinity similar to the fresh counterpart. This study highlights the importance of topotactic chemical reactions in structural repair and offers insights into the potential of targeted Li compensation for energy-efficient recycling of battery electrode materials with polyanion-type skeletons.
由于资源、环境和成本等因素的考虑，从电动汽车（EV）废旧锂离子电池（LIB）中回收磷酸铁锂（LiFePO）受到了广泛关注。通过中子衍射、X射线光电子能谱和透射电子显微镜，我们揭示了电池循环过程中锂的持续损失，导致锂缺乏状态（LiFePO）以及单个颗粒内的相分离，其中橄榄形磷酸铁（FePO）纳米域（5-10纳米）嵌入在LiFePO基质中。锂损失和相变过程中橄榄形骨架的保留使得材料得以回收。通过对锂损失进行化学补偿，我们成功地将混合的LiFePO/FePO结构恢复为纯LiFePO，消除了纳米晶粒边界。再生的LiFePO（R-LiFePO）表现出与新鲜材料相似的高结晶度。本研究强调了拓扑化学反应在结构修复中的重要性，并为通过有针对性的锂补偿实现具有聚阴离子型骨架的电池电极材料的节能回收潜力提供了见解。
