Tailoring Sieving Pores and Electrochemical Interface Intercalation for Mechanically Resilient Recycled Micro‐Silicon Anodes
Yunan Wei, Ruilin Wu, Shixin Liu, Han Liang, Runwei Mo
Abstract
Abstract To meet the demands of high‐energy lithium‐ion batteries, micron‐sized silicon (Si) anodes need to have high capacity, low expansion, long life, and fast charging characteristics. However, their industrialization is constrained by the fundamental contradiction between particle deformation and charge transfer. Here, an innovative strategy is proposed, using micron‐sized Si recovered from photovoltaic waste as raw material, combined with electrochemical lithium alloying and rapid heating, reacting with CO 2 and acid washing to obtain a sieve‐like porous structure design to overcome mechanical dynamic limitations. The structural design achieves extremely high capacity and low electrode expansion rate (10.8% at 2493 mAh g −1 and 8.72 mAh cm −2 ), excellent rate performance (1257 mAh g −1 and 4.4 mAh cm −2 at 2 A g −1 over 1000 cycles), and ultra‐low capacity decay rate (0.016% per cycle). The pouch cell achieves a capacity retention rate of 91.5% over 500 cycles and a record‐breaking volumetric energy density of 1428 Wh L −1 . In addition, a non‐destructive testing method based on the dp/|dQ| peak as a fault warning signal is also developed, which establishes a new method for early safety warning for Si‐based batteries. This work provides an efficient and environmentally friendly solution for the resource utilization of photovoltaic silicon waste.