Organic interlayer engineering of TiS2 for enhanced aqueous Zn ions storage

Aqueous rechargeable zinc-ion batteries (ARZIBs) have a bright future for energy storage due to their high energy density and safety. However, for traditional ARZIBs, cathode materials always suffer from the limited space for large-sized zinc ions storage and transport, leading to low Coulombic efficiency and inferior cycling performance. To build a reliable host with large tunnel, 1-butyl-1-methylpyrrolidinium ion (PY14+) pre-intercalated TiS2 (PY14+-TiS2) is designed as an alternative intercalation-type electrode. As the insertion organic guest widens the interlayer space of TiS2 and buffers the lattice stress generated during the electrochemical cycles, the structural reversibility, cycling stability and kinetics properties of PY14+-TiS2 are enhanced greatly. A specific capacity of 130.9 mAh g−1 with 84.3% capacity retention over 500 cycles can be achieved at 0.1 A g−1. Therefore, this study paves the way for enhancing the aqueous Zn ions storage capability by organic interlayer engineering.