How to simultaneously restrain the loss of active species and facilitate the conversion reaction under high S loading condition is the key to solve the commercialization of Li-S batteries. For this system, the availability of raw materials and simplicity (high efficiency) of synthetic strategies are also important factors. Herein, we propose an interlaced two-dimensional (2D) carbon material as advanced Li-S cathode host characterized by corrugated monolithic morphology and Co/N dopants as dual lithiophilic-sulfiphilic sites. This 2D structure is derived from a cheap biomass precursor, adenine, with bonding interaction with a MgCl2 hydrate template via a facile ionothermal method. It allows a homogeneous spatial distribution of S/Li2S deposits and strong adsorbability and enhanced conversion kinetics for polysulfides. Benefiting from the synergistic effects of corrugated 2D conductive matrix and embedded heteroatom/nanodot catalyst, the resultant sulfur cathode releases a high specific capacity of 1290.4 mA h g-1 at 0.2 C, small capacity fading rate of 0.029% per cycle over 600 cycles at 2 C, superior rate performance up to 20 C, and considerable areal capacity retention of 6.0 mA h cm-2 even under an ultrahigh sulfur loading up to 9.7 mg cm-2.
Keywords: Co/N-codoped carbon; adenine derivative host; high-loading Li−S batteries; interlaced 2D structure; lithiophilic−sulfiphilic sites.