Multi-hierarchical earbuds-ball-like silicon suboxide-carbon hybrids design for high-performance lithium storage

Abstract

Silicon suboxide (SiOx) is considered a promising substitute for silicon (Si) anode materials in lithium-ion batteries due to its high specific capacity (>2200 mAh g−1) and improved cycling performance. However, its volume expansion (∼200%) and low conductivity cannot be ignored. Here, inspired by earbuds, we design and mass synthesize (240 g h−1) the earbuds-like three-dimensional SiOx nanonetworks (3D-SiOx NNs) by a radio-frequency thermal plasma (RF-plasma) system. The spray drying technology is used to further accelerate the winding of 3D-SiOx NNs to prepare micron-sized multi-hierarchical earbuds-ball-like SiOx/C (E-SiOx/C) with enhanced elasticity and high tap density. As anodes, E-SiOx/C exhibits the high gravimetric/volumetric specific capacity of 1790 m Ah g−1/1137 m Ah cm−3 and excellent rate cycling performance (1480 m Ah g−1 at 2.0 A g−1 for 700 cycles). In addition, full battery constructed with LiNi0.5Co0.2Mn0.3O2 cathode exhibit high gravimetric energy density of 530.9 Wh kg−1 and impressive cycling performance (513.9 Wh kg−1 for 100 cycles), manifesting great promise for the application of high-performance batteries.