Metal-organic frameworks (MOFs)-derived Mn2SnO4@C anode based on dual lithium storage mechanism for high-performance lithium-ion capacitors

Abstract

Lithium-ion capacitors (LICs) are an emerging energy storage device that combines high energy density with high power density. Tin dioxide (SnO2) is considered a promising anode material due to its high theoretical capacity and low redox potential. However, severe volume expansion limits its practical application. In this study, a rhombic-shaped Mn2SnO4@C composite material with a uniform carbon coating was synthesized through pyrolysis of metal–organic frameworks (MOFs) and employed as an anode material for LIC. The material exhibited a dual lithium storage mechanism through alloying and conversion reactions. The Mn2SnO4@C anode exhibited excellent cycling stability due to the synergistic effect between Mn and Sn, and the uniform carbon coating. The anode maintained a capacity retention over 100 % at various current densities and a specific capacity reached 944 mAh g−1 after rate testing. Furthermore, a novel LIC was assembled using Mn2SnO4@C anode and coconut shell biomass carbon (CSBC) cathode, delivering an ultrahigh energy density of 217.9 Wh kg−1 at 210 W kg−1 and maintaining 25.1 Wh kg−1 even at a high power of 21 kW kg−1. This work applied alloy-conversion dual lithium storage mechanism anode materials to LICs, providing a new avenue for next-generation high-performance LICs.