Metal sulfide-decorated lamellar porous carbon framework hybrids for fast lithium storage with high volumetric capacity

Abstract

Porous carbon nanosheets have shown great potential in electrochemical energy storage devices, yet their intrinsic limited volumetric capacity and energy density remain a great concern. Herein, lamellar porous carbon framework hybrids (LPCFHs) have been facilely developed by thermal-induced bulk self-assembly of block copolymers with precisely controllable molecular structure, followed by stepwise chemical crosslinking and morphology-persistent carbonization processes. The as-obtained LPCFHs consist of densely covalent connected alternate layers (porous carbon nanosheets and porous carbon spacers) and homogenously dispersed metal sulfide nanoparticles. The ordered compact stacking structure of carbon nanosheets endows LPCFHs with a high tap density and fast electron transfer both in lateral and vertical dimension, while the porous carbon spacers enable fast channels for ion transfer. Moreover, the metal sulfide nanoparticles strongly interacted with carbon nanosheets are homogenously distributed in LPCFHs, resulting in sufficient active sites. As a result, when used as anode materials in lithium-ion batteries (LIBs), tin sulfide-decorated LPCFHs (LPCFHs-SnS) deliver a volumetric capacity of up to 1285 mAh cm−3; meanwhile, high-rate capability (488 mAh g−1 at 5 A g−1) and excellent cycling stability (capacity retention of 88.3 % after 500 cycles at 1 A g−1) are also achieved, demonstrating great potential for practical application in LIBs.