3D Carbon Coating Enabled High‐capacity and Stable Micro‐sized Silicon Suboxide‐graphite Blended Anodes for Practical Lithium‐ion Batteries
Abstract Silicon oxide (SiO x ) is a promising anode candidate of lithium‐ion batteries (LIBs) owing to its extremely high specific capacity. However, the low initial Coulombic efficiency (ICE) and rapid capacity degradation of SiO x , triggered by the enormous volume variation upon repeated (de)lithiation, gravely hinder its practical use. Herein, two mass‐produced micro‐sized SiO x @C composites with obviously different morphologies for commercial LIBs are reported. Particularly, the SiO x ‐graphite blended anode (SiO x @3D‐G‐Gr) based on SiO x wrapped by three‐dimensional (3D) carbon layers (SiO x @3D‐G) exhibits a capacity of 519 mAh g −1 , an ICE of 90.0 % and a capacity retention of 83.4 % at 0.2 C over 100 cycles. which is far exceeding its counterpart SiO x @C‐H‐Gr (65.7 %). The obtained impressive properties of SiO x @3D‐G originate from the critical contribution of 3D carbon layers, which serves as the effective stress buffer and protective layer as well as the strong networks for electron/Li + transport. Accordingly, the full‐cell based on SiO x @3D‐G‐Gr anode and commercial LiCoO 2 cathode delivers a capacity of 803 mAh and an excellent capacity retention of 95.6 % (616 mAh, 96.6 % for graphite, respectively) at 1 C over 100 cycles with a stabilized CE of nearly 100 %. The micro‐sized SiO x @3D‐G showing a promising prospect in the commercial‐grade anodes in LIBs.