Controllable Synthesis of Nitrogen-doped Graphene Oxide by Tablet-sintering for Efficient Lithium/Sodium-ion Storage

Mingxiang Hu 1

Qian Lv 1

Ruitao Lv 1, 2, Email

1 State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China

2 Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China

Abstract

Heteroatom doping is an efficient way to tailor the electrochemical properties of carbon-based energy storage materials. However, synthesizing nitrogen-doped carbon materials with a high doping level (e.g. over 10.0 at.% N content) and controllable doping contents is very challenging. Herein, a tablet-sintering method using two nitrogen sources (ammonia and urea) is proposed to realize the regulation of nitrogen contents in the carbon materials from 4.8 at.% to almost 12.0 at.%. Optimized sample with 10.1 at.% nitrogen content demonstrates excellent pseudocapacitive behaviors with 104.1 F g-1 and 176.3 F g-1 for the lithium- and sodium- ion capacitorsin organic electrolytes at 1 A g-1. Moreover, highly doped nitrogen could promote the cycling stability of carbon-based materials high voltage (up to 5.0 V) in the ionic liquid electrolyte. This may open a new avenue for the chemical doping of carbon-based materials and their applications in high-performance electrochemical devices.

Controllable Synthesis of Nitrogen-doped Graphene Oxide by Tablet-sintering for Efficient Lithium/Sodium-ion Storage