Constructing layered double hydroxide fences onto porous carbons as high-performance cathodes for lithium-sulfur batteries

摘要

Benefiting from the ultrahigh specific surface area, tunable pore size, and abundant surface functionality, biomass derived carbons (BC) are thriving as promising conductive matrices to host sulfur for Li-S battery cathodes. Unfortunately, pristine BC still suffers from awful cycling performance rooted in their limited physical/chemical adsorption ability towards polysulfide. Herein, we proposed to construct Nickel Aluminum Layered Double Hydroxides (NiAl-LDH) fences coated on H3PO4 activated BC (PAB) as an efficient sulfur host. The decorated NiAl-LDH fences could efficiently reinforce both chemical adsorption and physical confinement effects on polysulfides, and render as an electrocatalyst to significantly boost the redox reaction kinetics. Furthermore, the DFT simulation has been employed to illustrate enhanced interaction forces towards polysulfides. As a result, the prepared NiAl@PAB/S cell exhibits an improved performance of 1216.3 mAh g(-1) initially at 0.2C (1C = 1672 mAh g(-1)), excellent cycling stability during 300 cycles at 1 C (0.13% decay rate per cycle), and superior rate capability up to 3 C (614.2 mAh g(-1)). This work provides a cost-efficient and effective method to significantly improve the overall performance of porous-carbon-based Li-S battery cathode. (C) 2019 Elsevier Ltd. All rights reserved.