Nanoconfined Oxidation Synthesis of N-Doped Carbon Hollow Spheres and MnO2 Encapsulated Sulfur Cathode for Superior Li-S Batteries

Jiadong Shen; Jun Liu; Zhengbo Liu; Renzong Hu; Jiangwen Liu; Min Zhu

doi:10.1002/chem.201704590

Nanoconfined Oxidation Synthesis of N-Doped Carbon Hollow Spheres and MnO₂ Encapsulated Sulfur Cathode for Superior Li-S Batteries

Chemistry. 2018 Mar 26;24(18):4573-4582. doi: 10.1002/chem.201704590. Epub 2018 Jan 16.

Authors

Jiadong Shen^{1

2}, Jun Liu^{1

2}, Zhengbo Liu^{1

2}, Renzong Hu^{1

2}, Jiangwen Liu^{1

2}, Min Zhu^{1

2}

Affiliations

¹ School of Materials Science and Engineering and Guangdong Provincial, Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641, P.R. China.
² SUNWODA-SCUT Joint Laboratory for Advanced Energy Storage Technology, South China University of Technology, Guangzhou, 510641, P.R. China.

PMID: 29181856
DOI: 10.1002/chem.201704590

Abstract

The sulfur cathode, as a new generation of lithium-ion battery cathode material, has a high theoretical energy density of about 2500 Wh kg^-1 . However, the low conductivity of sulfur and the "shuttle effect", widely presenting in the lithiation/de-lithiation process, seriously hinder its practical application. Here, we report a new nanoconfined oxidation route (first complete oxidation of metal sulfide and subsequently partial oxidation of the generated S from sulfide) for S cathode encapsulated with MnO₂ nanosheets and N-doped carbon hollow spheres. This nanoconfined oxidation route can successfully confine the sulfur particles in the interior of the carbon shell, and the rationally introduced nonpolar carbon and polar MnO₂ can both reduce the dissolution of polysulfide during the charge-discharge process. The obtained well-defined S-MnO₂ @C cathode exhibits high specific capacity with excellent cycling performance and superior rate capability.

Keywords: Li-S batteries; N-doped carbon; cathode material; encapsulating structure; nanoconfined oxidation.