Ordered mesoporous carbon (OMC) is a promising candidate for the anode of sodium-ion batteries (SIBs). However, low electronic conductivity and scanty defects are the bottlenecks that result in the unsatisfied electrochemical performance. A team from the key laboratory of coal science and technology of Taiyuan University of Technology demonstrate the nitrogen and sulfur co-doped strategy to modify the OMC, and thus enhance its sodium storage capacity. Their research has been published on February 1st, 2019 in Journal of Power Sources.

Figure1 The coordination structures and surface functional groups of heteroatoms doped OMC are determined by the experiments carried out at BSRF. The increased defects and the abundance of graphitic and pyridinic nitrogen species endow the enhancement of sodium storage capacity.

The team fabricated N/S co-doped OMC using a simple thermal treatment with thiourea. The obtained N/S co-doped OMC with enhanced electronic conductivity and abundant defects, endowing the materials superior sodium storage properties. The research provides implications for the design of carbon based SIBs anodes. Synchrotron sources have helped the team to unveil the change of the electronic structures of OMC after the heteroatoms were incorporated, and the results revealed the abundance of graphitic and pyridinic nitrogen species, which favors the enhancement of electronic conductivity and sodium storage capacity. The ointment is that the evolution of nitrogen and sulfur species during the electrochemical reaction still needs further investigation, and thus the in-situ synchrotron facility would surely help to unveil this process.

Article:

Jianqi Ye, Hanqing Zhao, Wei Song, Na Wang, Mengmeng Kang, Zhong Li, Enhanced electronic conductivity and sodium-ion adsorption in N/S co-doped ordered mesoporous carbon for high-performance sodium-ion battery anode [J]. Journal of Power Sources 412 (2019) 606–614.