Local Microenvironment-Induced Dynamic Self-Adaptation for High-Performance Ammonium-Ion Batteries

Rechargeable aqueous ammonium-ion batteries (AIBs) have emerged as a highly promising energy storage system due to their safety and cost-effective sustainability. However, the design of AIBs electrodes that exhibit high-rate capability and a long cycle life to meet practical requirements is difficult. To address this challenge, we propose a local microenvironment-induced dynamic self-adaptation strategy. By constructing an amorphous layer in the microenvironment region of the vanadium oxide surface, we demonstrate that the local chemical microenvironment triggers reversible structural evolution during NH₄⁺ de/intercalation. The tailored microenvironment at crystalline-amorphous interfaces spontaneously generates self-adaptive domains that dynamically counteract cycling-induced stresses and accelerate electron conduction. Therefore, the SR-VO half-cell achieves exceptional cycling stability and rate performance (an ultralow decay rate of 0.004% per cycle at 10 A g^-1 after 10,000 cycles with 83.4 mAh g^-1). The full cell integrating SR-VO with a high-entropy Prussian blue cathode demonstrates practical viability by powering wearable devices. This work highlights the critical role of heterostructure engineering in overcoming AIBs material limitations and advancing their practical applications.