Effects of binders on electrochemical properties of the SnS 2 nanostructured anode of the lithium-ion batteries

Binders play a significant role in enhancing the electrochemical performance of tin disulfide (SnS2) as the anode for lithium-ion batteries (LIBs) because of their excellent dispersion and cohesion in the electrodes. In the present work, flake-like SnS2 nanoparticles with a hexagonal structure were synthesized by a facile one-step hydrothermal method with a mean grain size of 7.7 nm. When sodium alginate (SA), carboxymethyl cellulose (CMC), poly acrylic acid (PAA), and CMC-PAA (1:1, wt%) are applied as binders for the SnS2 anode electrode (the obtained electrodes are denoted as SnS2-S, SnS2-C, SnS2-CP, and SnS2-P, respectively) in LIBs, the electrodes exhibited high reversible lithium-ion storage capacities of 762.00 mA h g−1, 891.65 mA h g−1, 913.94 mA h g−1, and 930.36 mA h g−1 at the current densities of 100 mA g−1, respectively. Importantly, the SnS2-P electrode exhibited excellent rate capacity and cycling performance. The –COOH of PAA attached to SnS2 can increase the amount of free radicals, which can prevent the detachment of SnS2 from the current collector, and the carboxyl group can effectively inhibit the volume expansion and pulverization of particles of the electrode. Undoubtedly, PAA binder significantly improves the cycling and rate performances of SnS2 anode material for LIBs.