3D porous framework of ZnO nanoparticles assembled from double carbon shells consisting of hard and soft carbon networks for high performance lithium ion batteries.
Nanotechnology
; 31(28): 285402, 2020 Apr 24.
Article
em En
| MEDLINE
| ID: mdl-32209746
ABSTRACT
Low electronic conductivity and large volume variation result in inferior lithium storage performance of ZnO. To overcome these shortcomings of ZnO, herein ZnO nanoparticles are encapsulated in resorcinol-formaldehyde resin-derived hard carbon and then further assembled into a 3-dimensional mesoporous framework structure using a polyvinyl pyrrolidone-derived soft carbon network. The synthesis methods include the polymerization of resorcinol-formaldehyde resin and a polyvinyl pyrrolidone-boiling method. ZnO@dual carbon has af large specific surface area (153.7 m2 g-1) and high porosity. It exhibits excellent cycling performance and high rate capability. After 350 cycles at 500 mA g-1, the ZnO@dual carbon still delivers a discharge capacity of 701 mAh g-1 while the actual discharge capacity of ZnO reaches 950.9 mAh g-1. At 2 A g-1, ZnO@dual carbon delivers the average discharge capacity of 469.6 mAh g-1. The electrochemical performance of ZnO@dual carbon is remarkably superior to those of ZnO@single carbon, pure carbon and pure ZnO nanoparticles, demonstrating the superiority of the dual carbon-assembly structure. This composite structure greatly improves the structural stability of ZnO, enhances its electron conductivity and overall electron transport capacity; which facilitates electrolyte penetration and Li ion diffusion, leading to improved cycling stability and good rate capability.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article