Scalable production of 3D plum-pudding-like Si/C spheres: Towards practical application in Li-ion batteries

Abstract

Nanosized silicon (Si) has been widely investigated as a promising material for next generation lithium-ion battery (LIB) anodes because of its ultrahigh capacity. However, only a few results can satisfy all aspects towards practical application, particularly the problems like low initial Coulombic efficiency, low volumetric capacity, huge volume change (>290%), complicated fabrication methods, and especially low production remain unsolved. Here, we propose a 3D plum-pudding-like Si/C micro-/nano- composite (SiNS/C) design for an anode via quasi-industrial-scale production that tackles all these problems: large-scale production of ~300 g/h, ultra-high initial Coulombic efficiency (ICE) of 88%, high volumetric capacity of ~1244 mA h cm-3, and improved rate capability have been achieved. An in-situ high-resolution transmission electron microscopy (HRTEM) probing has testified that a design of Si/C nanospheres with the appropriate size enables only small volume variations (upon lithiation), e.g. ~48% for 50 nm Si/C spheres in the SiNS/C particles as required for the practical applications, and leads to the formation of a stable thin SEI layer on the outer surface of carbon coating layer.