Constructing Gradient Porous Structure in Thick Li₄Ti₅O₁₂ Electrode for High-Energy and Stable Lithium-Ion Batteries

Abstract

The manufacturing process for electrodes in lithium-ion batteries generally results in a nonuniform microstructure geometrically distributed in the through-thickness direction of an electrode. A porous structure was designed to decrease tortuosity and increase Li+ penetration in a thick Li4Ti5O12 (LTO) electrode. By using NaCl as a template, the porous LTO electrode with a high mass loading of 12 mg cm–2 was fabricated. Electrochemical performance for the LTO electrode with different porosities was comparatively studied. To achieve higher volume energy density, a gradient porous LTO electrode was prepared. As a result, the thick LTO electrode with a high mass loading of 20 mg cm–2 can deliver a high capacity of 150 mAh g–1 at 1 C with almost no ohmic drop under charge/discharge for 40 cycles.