Three-dimensional nitrogen–sulfur codoped layered porous carbon nanosheets with sulfur-regulated nitrogen content as a high-performance anode material for potassium-ion batteries. Issue 16 (25th March 2020)

• Record Type: Journal Article
• Authors: Zhang, Ying; Tian, Sheng; Yang, Chenghao; Nan, Junmin
• Is Part Of: Dalton transactions. Volume 49:Issue 16(2020)
• Page Start: 5108
• Page End: 5120
• Publication Date: 2020-03-25
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt00697a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Through the gel and nitrogen-sulfur co-doping process, a three-dimensional nitrogen-sulfur co-doped layered porous carbon nanosheet with adjusted nitrogen content was constructed as a high-performance anode material for potassium ion batteries. Abstract : Three-dimensional nitrogen–sulfur codoped layered porous carbon nanosheets (3D-NSCNs) with sulfur-regulated nitrogen content are constructed as a high-performance anode material for potassium-ion batteries (KIBs) through a gel and nitrogen–sulfur codoping process. Compared with the sample without sulfur doping, the 3D-NSCNs reveal enhanced electrical conductivity, specific surface area, and pyrrolic (N-5) and pyridinic (N-6) nitrogen contents, all of which are beneficial for increased electrochemical performances. After 200 cycles at a current density of 100 mA g −1, the 3D-NSCNs anode exhibits a specific capacity of 254.9 mA h g −1 . After 2900 cycles at a higher charge–discharge current density of 1 A g −1, the specific capacity is still 171.1 mA g −1, and the capacity retention is 78.9%, indicating the application potential of the as-synthesized 3D-NSCNs as an anode material for KIBs. Domination by a surface-driven mechanism is proposed to explain the excellent rate and cycle performances and can also be validated by galvanostatic intermittent titration results, which show that the K + diffusion coefficient in the 3D-NSCNs is improved after nitrogen–sulfur doping. This work demonstrates a new strategy to improve the electrochemical properties of carbon-based K-storage materials by increasing the N-5 and N-6 contents through sulfur doping while also producing micropores to increase the number of active sites.