Manipulation of lithium dendrites based on electric field relaxation enabling safe and long-life lithium-ion batteries

Lithium dendrites, with their high reactivity, pose a critical challenge to the safety and longevity of lithium-based batteries. Effective regulation strategies are crucial for mitigating battery degradation and enhancing reliability. Conventional approaches, such as relaxation following lithium plating or regulated discharging, often fail to simultaneously address the formation of solid electrolyte interface and isolated lithium. Here, we demonstrate that rational utilization of electric field relaxation following dendrite growth can reduce defective solid electrolyte interface and isolated lithium by balancing solid electrolyte interface growth and dendrite morphology smoothing near the relaxation time constant. Building upon the mechanism, we propose a short-term relaxation method to manipulate lithium plating, which achieves an enhancement of capacity retention from 80% up to 95% at 3 C-rate (20 min) fast-charging on commercial batteries. These findings highlight the importance of relaxation after dendrites formation for safe, long-life and fast-charging batteries, particularly where dendrite growth is the limiting factor. Dendrite growth harms the safety and longevity of Li-ion batteries. Here, authors find that short-term relaxation after lithium plating boosts capacity retention by forming a beneficial solid electrolyte interphase and smoothing morphologies, providing an approach for safe and long-life batteries.