Titanium dioxide nanotube arrays (TNTAs) as an effective electrocatalyst interlayer for sustainable high-energy density lithium-sulfur batteries

Free-standing titanium nanotube arrays (TNTAs) interlayer has been developed and applied to improve the electrochemical performance of Li-S batteries. Results and DTF simulation confirmed that the strong electrochemical interaction of lithium polysulfides (LiPSs) with TNTAs supported by a carbon-coated separator (CCS), suppressed the shuttling effect significantly. The presence of TNTA resulted in stable cycling and superior rate performance by offering a specific discharge capacity of 1050 mA h g−1 after 300 cycles at 0.5 C with a low capacity-decay rate of 0.075% per cycle. The cathode with the loading of 6.8 mg S cm−2 delivered a discharge capacity of 729 mA h g−1, corresponding to 4.95 mA cm−2 after 100 cycles at the rate of 0.2 C. The outperformance of the cell equipped with TNTAs became more attractive when the cathode with the loading of 3 mg S cm−2 has been fabricated with the simple blade-casting method using sulfur powder. The sulfur cathode delivered a superior discharge capacity of 905 mA h g−1 after 100 cycles with Coulombic efficiency> 97%. The results have demonstrated that the coexistence of TNTAs, CCS and sulfur cathode in the pure phase offers an efficient strategy to achieve a high-energy density for sustainable sulfur-based energy storage systems. © 2021 Elsevier B.V.