Abstract:
Due to the low cost, high safety and easy assembly, rechargeable aqueous zinc-manganese oxide (Zn-MnO
x) batteries are the best devices for energy storage. However, poor conductivity of MnO
x results in the bad cycle performance. Herein, highly conductive and layered Ti
3C
2T
x MXene with rich terminations (T
x, for example, =O, —F, —OH) were used as carriers for MnO
x particles. Due to the electronegativity of the terminations, Mn
2+ was intercalated into the layers and adsorbed on the surface of Ti
3C
2T
x MXene, making the generated Mn
3O
4 particles can firmly anchored, forming the Ti
3C
2@Mn
3O
4 composites. As for the cathode of zinc-ion batteries, Ti
3C
2@Mn
3O
4 was fully converted to Ti
3C
2@ε-MnO
2 during the 1st charge process. Thanks to the excellent conductivity and layered structure of Ti
3C
2T
x MXene, Ti
3C
2@ε-MnO
2 cathode presents excellent kinetic properties and electrochemical performance with a high specific capacity of 440 mA·h·g
−1 and high energy density (607 W·h·kg
−1) at 0.2 C (1 C=308 mA·h·g
−1), and the capacities increase from 270 mA·h·g
−1 to 480 mA·h·g
−1 after 150 cycles at 1 C. Excellent electrochemical performance, simple material preparation methods, combined with the low cost, high safety and easy assembly characteristics, enable the possible application of rechargeable aqueous Zn-MnO
x batteries in large-scale energy storage.