3D Ordered Porous Nanostructure Confers Fast Charge Transfer Rate and Reduces the Electrode Polarization in Thick Electrode

Small. 2022 Feb;18(7):e2104224. doi: 10.1002/smll.202104224. Epub 2021 Dec 5.

Abstract

Lithium batteries with high electrode thickness always possess a poor battery property due to electrode polarization along the thickness direction. Herein, a concept that the electrode polarization can be reduced through the fabrication of 3D ordered interconnected nanostructure in the electrode is put forward. A nitrogen-doped carbon photonic crystal (NCPC) with the ordered interconnected nanostructure is used in the electrode to prove the concept. NCPC can provide a fast charge transfer rate along the thickness direction and a uniform distribution for electrons and lithium ions, resulting in diminishing the concentration polarization and concentration gradient. When NCPC works for lithium-sulfur battery, the thick electrode achieves a fast charge transfer rate and a small voltage gap as well as the thin electrode. The 200 µm thick sulfur cathode obtains a specific capacity (87%) as high as 100 µm thick sulfur cathode. In contrast, the capacity ratio of the electrode made by the traditional coating method is only 45%.

Keywords: 3D; fast charge transfer; ordered porous nanostructures; photonic crystals; uniform charge distribution.