Arsenene, antimonene and bismuthene as anchoring materials for
lithium-sulfur batteries: a computational study
Abstract
Finding effective anchoring materials for the immobilization of soluble
lithium polysulfides to suppress the shuttling effect has become the key
to large-scale application of lithium-sulfur (Li–S) batteries. In this
work, the potentials of group-VA two-dimensional (2D) materials
including arsenene, antimonene and bismuthene (As, Sb and Bi monolayers)
as Li-S battery cathode anchoring materials were systematically
investigated by density functional theory (DFT) calculations. The
adsorption energies of sulphur (S8) and various lithium polysulfides
(Li2Sn, n = 8, 6, 4, 2, 1), as well as the diffusion energy barriers for
long-chain Li2S4 and Li2S6 on these three monolayers were studied in
detail. The calculated moderate adsorption energies of these monolayers
to all polysulfides imply that they can effectively inhibit the
shuttling effect. The favorable diffusion barriers for Li2S4 and Li2S6
ensure the efficient diffusion of polysulfides on monolayer surface. In
addition, these 2D materials can keep a balance between the binding
strength and the structural integrity of polysulfides. The presented
merits demonstrate that As, Sb and Bi monolayers can be the promising
cathode anchoring materials to improve the performance of Li-S
batteries.