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The uneven electrochemical reactions of lithium (Li) metal anode is one of the main reasons that hinder its application in rechargeable high energy density batteries. Great progress has been achieved in homogenizing electrochemical reactions of Li metal anode in lab‐scale coin cells, however, it cannot be directly applied to pouch cells, where undesirable defects or side reactions are significantly aggravated. With carbonate electrolyte, multi‐layered negative and positive electrodes (8 × 11 cm), 1.2 Ah sulfurized polyacrylonitrile (SPAN)||Li pouch cell lost all its capacity after 40 cycles under a current of 600 mA, although its counterpart with coin cell configuration showed much higher capacity retention of 94% under the same test condition. Severe corrosion with uneven, porous, dendritic Li deposits is observed for pristine Li electrode in a pouch cell, especially in the near‐tap and the central regions with close connection with the current collector due to the locally amplified current densities. In contrast, Li/Li–Sn alloy composite electrode displays uniform and dense Li plating behavior over the entire test area with significantly suppressed parasitic reactions and gas evolution. As such, a 1.2 Ah SPAN||Li/Li–Sn cell displays much higher capacity retention than SPAN||Li cell (87% for 100 cycles vs. 0 for 40 cycles). [ABSTRACT FROM AUTHOR]

The recycling of LiFePO 4 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 (Li 1- x FePO 4 ) and phase separation within individual particles, where olive-shaped FePO 4 nanodomains (5-10 nm) were embedded in the LiFePO 4 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 4 /FePO 4 structure to pure LiFePO 4 , eliminating nanograin boundaries. The regenerated LiFePO 4 (R-LiFePO 4 ) 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.