Arginine Interfacial Regulation Strategy for Enhanced Cycling Stability of SiOx Anodes

Abstract: This study addresses two critical challenges associated with silicon-based anodes in lithium-ion batteries, severe volume expansion and interfacial instability. To propose an interfacial regulation strategy in which SiOx anodes are coated with arginine solutions of different molar concentrations, thereby promoting the in situ formation of a LiF-rich inorganic phase within the SEI during cycling. This strategy markedly enhances interfacial stability while effectively mitigating electrode volume expansion upon lithiation/delithiation, leading to improved electrochemical performance. In Li‖SiOx/arginine half-cells, the capacity retention at 0.5C remains close to 100% after 100 cycles, whereas the unmodified SiOx electrode decays to 498.3 mAh·g-1, demonstrating substantially enhanced cycling stability. At 2C, the arginine-coated electrode delivers a high specific capacity of 576.38 mAh·g-1. Further morphological analysis reveals that the electrode swelling ratio decreases from 95.6% to 34.7%, confirming improved structural integrity. Overall, this work provides a new route for constructing a stable SEI on SiOx anodes and offers a simple yet effective solution for developing high-performance silicon-based lithium-ion batteries.