Hierarchical Nanoporous N-Doped Carbon for Enhanced Rate Performance of Lithium-Ion Battery Anodes

Abstract

At the nanoscale, the graphitic degree, surface area, and heteroatom doping are primary properties of any carbon material that influences anode performance for Li-ion battery (LIB) applications. The simultaneous control over nanostructured properties such as doping and surface area at the nanolevel remains challenging for achieving fast operating LIB. Here, we demonstrate a study on nitrogen-doped hierarchically nanoporous carbon (HNC) materials with specific dopant concentrations and tunable surface areas designed strategically via a dual-templating approach. The 3D nanoporous microflowers provide pathways to the lithium reservoir for fast charge-discharge. We explore the effect of different ammonia concentrations on nitrogen doping levels and the surface area of HNCs. Our findings reveal that consistently high surface area and excess nitrogen doping levels do not confer benefits. High-rate battery performance can be achieved at the expense of any of these properties. Using optimized HNC, we achieved a high-rate performance of 357 mAh g-1 at 2 A g-1 and approximately 87% stability retention after 600 cycles, showcasing its potential for LIB applications.