Polypyrrole-Encapsulated Polyoxomolybdate Decorated MXene As a Functional 2D/3D Nanohybrid for a Robust and High Performance Li-Ion Battery

We have synthesized polypyrrole-encapsulated polyoxomolybdate (PMo12) decorated Ti3C2Tx MXene (PMo12@PPy/Ti3C2Tx) by a facile synthetic method and examined it as an anode material for lithium storage. Owing to the properties of electrostatic repulsion and self-assembly of PMo12-anions, the PPy molecules wrap the individual PMo12 anions and help with the successful intercalation between the layers of Ti3C2Tx. Consequently, the composite electrode exhibits superior lithium storage with high capacity (764 mAh g–1 at 0.1 A g–1), long cycling stability even at a high current rate (2000 cycles at 3 A g–1), and impressive rate performance. This unique 2D/3D architecture exhibits hybrid battery-capacitive behavior due to the synergistic effect between PPy encapsulated PMo12 and Ti3C2Tx. The battery component is a result of reversible redox reactions of metal ions (Mo), while the pseudocapacitive component is contributed by PPy and Ti3C2Tx. These results suggest that suitably engineered MXene based hybrid materials hold great potential in the domain of energy storage.