WANG Ming (1982-), male, Ph.D., Associate Professor. E-mail: wangming@lntu.edu.cn.
Silicon has attracted wide attention due to its high theoretical specific capacity. However, the huge volume change and poor reaction kinetics in the lithiation process lead to a serious deterioration of its structure, a continuous capacity attenuation and a poor magnification performance, thus restricting its practical application. To solve these problems, silicon/reduced graphene oxide (Si/rGO) nanocomposites with a three-dimensional cage-like conductive structure were designed by an in-situ electrostatic self-assembly and hydrothermal reduction method with commercial Si nano-particles with the size of 60 nm and natural flake graphite. The lithium ion storage performance and energy storage mechanism of Si/rGO nanocomposite were investigated. The results show that Si nano-particles are uniformly encapsulated into a three-dimensional cage-like conductive network structure of rGO, effectively limiting the volume expansion of nano-Si particles and providing the more ion transport channels in the process of lithium ion intercalation/detachment. The specific capacity of Si/rGO nanocomposites is 1 246 mA·h/g at 0.1 A/g. The Coulomb efficiency is 98.2% and the capacity retention is 95.5% from fifth cycle, indicating that the nanocomposite has a fast stability behavior. The reversible capacity remains 852 mA·h/g, the Coulomb efficiency is 99.9%, and the capacity retention is 68.4% after 200 cycles.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |