Ti₃C₂ MXene with pillared structure for hybrid magnesium-lithium batteries cathode material with long cycle life and high rate capability

Cationic surfactants (CS) pillared Ti₃C₂ composites (Ti₃C₂/CS) were prepared by a facile electrostatic assembly method, which have large interlayer spacing and slight N-doping. In hybrid magnesium-lithium batteries (HMLBs), the Ti₃C₂/CS composites exhibit excellent performance by utilizing both Li⁺ and Mg²⁺ as charge carriers. Among these composites, the Ti₃C₂/CTAB (CTC) electrode displays a reversible capacity of 115.9 and 60 mAh g⁻¹ in APC/LiCl (APCL) and APC electrolytes at 0.1 A g⁻¹, and it also exhibits excellent high rate performance and ultralong cycle performance. It is verified that CS is vital to significantly improve the diffusion kinetics of Mg²⁺ on the electrode surface. The CS can act as the conductive “bridge” which connects different Ti₃C₂ layers and the interlayer pillar which expands the interlayer distance. In addition, the N element in CS is effective in neutralizing electronegativity and enhancing electrical conductivity for the CTC electrode. The electrode design strategy can adapt to the synthesis of cathode materials with high rate capability in HMLBs.