Toward Practical High-Energy Batteries: A Modular-Assembled Oval-Like Carbon Microstructure for Thick Sulfur Electrodes

Adv Mater. 2017 Dec;29(48). doi: 10.1002/adma.201700598. Epub 2017 Apr 21.

Abstract

The modular assembly of microstructures from simple nanoparticles offers a powerful strategy for creating materials with new functionalities. Such microstructures have unique physicochemical properties originating from confinement effects. Here, the modular assembly of scattered ketjen black nanoparticles into an oval-like microstructure via double "Fischer esterification," which is a form of surface engineering used to fine-tune the materials surface characteristics, is presented. After carbonization, the oval-like carbon microstructure shows promise as a candidate sulfur host for the fabrication of thick sulfur electrodes. Indeed, a specific discharge capacity of 8.417 mAh cm-2 at 0.1 C with a high sulfur loading of 8.9 mg cm-2 is obtained. The large-scale production of advanced lithium-sulfur battery pouch cells with an energy density of 460.08 Wh kg-1 @18.6 Ah is also reported. This work provides a radically different approach for tuning the performance of a variety of surfaces for energy storage materials and biological applications by reconfiguring nanoparticles into desired structures.

Keywords: lithium-sulfur batteries; modular-assembly; oval-like microstructure; practical high-energy batteries; thick sulfur electrodes.