Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5149929 | Journal of Power Sources | 2016 | 9 Pages |
Abstract
A Li4Ti5O12(LTO)/N-doped reduced graphene oxide (RGO) composite is proposed using dual functional nitrogen doping source to prevent RGO restacking and achieve uniform nitrogen doping on RGO sheets to increase the rate performance of high-rate lithium ion batteries. The pore structure (both meso- and macro pores) is developed when RGO restacking is prevented, facilitating electrolyte ion diffusion to active sites with lower resistance. Uniform nitrogen doping on RGO sheets with high nitrogen contents provides additional free electrons to the sheets, resulting in increased electronic conductivity. Cyanamide is used as the nitrogen doping source for the N-doped RGO as well as a nanospacer between the RGO sheets. In the composite, the nitrogen content of the RGO sheets is 2.3 wt%, which increases the electronic conductivity of the composite to 1.60 S cmâ1. The specific surface area of the composite is increased to 35.8 m2 gâ1. Thus, the composite structure with the N-doped RGO sheets and porous secondary particles has high electrical conductivity and high ion accessibility. The LTO/N-doped RGO composite demonstrates excellent electrochemical performance with a low resistance of 48.4 Ω, a high specific capacity of 117.8 mAh gâ1 at 30 C, and good cycle stability.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Jun Hui Jeong, Myeong-Seong Kim, Young-Hwan Kim, Kwang Chul Roh, Kwang-Bum Kim,