Nondestructive electrical activation enables multiple life cycles for degraded batteries

Appropriate treatment of mass-produced degraded batteries is desired to alleviate resource waste and environmental pollution caused by direct disposal. However, current technologies, which aim to recycle high-value components from degraded batteries to refabricate new batteries, suffer from complex destruction-refabrication processes and massive energy/resource inputs. Here it is found that without disassembling the degraded battery, the lost capacity is rejuvenated to its pristine state by simply applying electrical activation at a controlled voltage. It is shown that repeated application of electrical activation regenerates 22 life cycles for zinc-ion batteries, increasing the total discharge energy by 78 times. The capacity rejuvenation by electrical activation originates from the transformation of redox-inert Zn-Mn-O by-products on the degraded cathode to redox-active Mn-O nanoribbons, which recovers diffusion kinetics of Zn${}^{2+}$/H${}^{+}$ charge carriers. Simultaneously, the dendrites on the degraded anode are flattened to prevent short circuits while maintaining the electrolyte integrity. The electrical activation strategy is extendable to other batteries, such as lithium batteries, promising tremendous economic and environmental benefits. Besides, electrical activation rejuvenates implanted batteries to avoid the pain and hazards of replacing degraded batteries with conventional surgeries. This work presents a general and commercially viable route to treat degraded batteries. (© 2024 Wiley‐VCH GmbH)