Scalable synthesis of spherical Si/C granules with 3D conducting networks as ultrahigh loading anodes in lithium-ion batteries

The practical application of Si-based materials has long been impeded by the high-cost, complicated fabrication technology and poor electrochemical performance. Herein, Si/C granules with novel structure are optimally designed and synthesized via a facile and scalable fabrication process. The obtained Si/C anodes exhibit excellent electrochemical performance at high mass loading (8.5 mg cm-2) because of the 3D conducting network and high tap density. Moreover, the cycling performance of Si/C anodes still remains stable even when the calendered density is increased to the level of commercial graphite anodes (1.6 g cm-3). Furthermore, Si/C anodes with various reversible capacities (450–750 mA h g-1) could be fabricated by the flexible production process. The pouch cell using Si/C anode and LiNi0.5Co0.3Mn0.2O2 cathode successfully demonstrates the practicability of Si/C anodes by powering electronic devices. The superior properties of full cell indicate that the spherical Si/C granules are an attractive alternative toward the practical application in Li-ion batteries.