In Situ Grown 1T′‐MoTe<sub>2</sub> Nanosheets on Carbon Nanotubes as an Efficient Electrocatalyst and Lithium Regulator for Stable Lithium–Sulfur Full Cells
Jiarui He, Amruth Bhargav, Arumugam Manthiram
Abstract
Abstract Lithium–sulfur batteries offer the advantage of high energy density at a low cost, but their viability is hindered by the polysulfide shuttle effect, sluggish reaction kinetics, and dendritic Li growth. To address these persistent challenges in a unified manner, a dual‐function, flexible, free‐standing framework by coupling catalytic and lithiophilic 1T′‐MoTe 2 nanosheets with conductive carbon nanotubes (MoTe 2 ‐CNT), which serve as a host for both a sulfur cathode (S/MoTe 2 ‐CNT) and a lithium‐metal anode (MoTe 2 ‐CNT/Li) is presented here. MoTe 2 ‐CNT not only guides a uniform growth of lithium within the framework, but also forms a thin, unique sulfide‐rich solid‐electrolyte interphase (SEI) composed of lithium thiotellurate on the Li surface when paired with a sulfur cathode. This SEI stabilizes Li deposition, suppresses electrolyte decomposition, and prevents Li loss, thereby prolonging cycle life. Full coin cells with a very low negative to positive electrode capacity ratio of ≈2.5 and a high areal capacity of 7.6 mA h cm −2 display 75% capacity retention after 500 cycles. The pouch cells fabricated with MoTe 2 ‐CNT deliver a high capacity of 1533 mA h g −1 and energy density of 319 Wh kg −1 at a low electrolyte‐to‐capacity ratio of ≈2.9 µL [mA h] −1 and a low electrolyte‐to‐sulfur ratio of 4.5 µL mg −1 .