SnO2/SnS2 heterostructure@ MXene framework as high performance anodes for hybrid lithium-ion capacitors

Among all kinds of energy storage devices, lithium-ion capacitors (LICs) emerged victorious because of their advantages of high energy densities and power densities. The main issue that limits the performance of LICs is the mismatch in reaction kinetics caused by the disparate energy storage mechanisms of the positive and negative materials. Herein, a Sn-based heterostructure@ MXene anode material was synthesized to achieve excellent rate performance and to increase the lithium storage capacity, which enables a good match with the cathode. In the synthesized hybrid electrode, the heterostructure can regulate the charge transmission at interfaces and improve the kinetics of electron conduction and ion diffusion. Meanwhile, the highly conductive MXene can buffer the large volumetric change of SnS2/SnO2 nanoparticles, and synergically improve electrochemical properties of the hybrid electrode. The hybrid electrode exhibited remarkable rate performance and cycle stability, showing 619 mAh g(-1) at 0.5 A g(-1) after 200 cycles, which greatly reduced the kinetic gap with capacitor-type cathodes. The assembled LICs based on the SnS (2)/SnO2@MXene hybrid anode and nitrogen-doped activated carbon (N-AC) cathode offer a high power/energy density (maximum 11.25 kW kg(-1) and 145.2 Wh kg(-1)) and a long cycling life (93.6% capacity retention after 2000 discharges/charges). This unique structure and the composition design provide a promising path for the fast kinetic LICs anode materials. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Among energy storage devices, lithium-ion capacitors (LICs) stand out due to their high energy densities and power densities. However, the mismatch in storage mechanisms between the positive and negative materials limits the performance of LICs. In this study, a Sn-based heterostructure@MXene anode material was synthesized to achieve excellent rate performance and increased lithium storage capacity, leading to a better match with the cathode. The hybrid electrode demonstrated remarkable rate performance and cycle stability, reducing the kinetic gap with capacitor-type cathodes. Assembled LICs based on this hybrid anode and nitrogen-doped activated carbon cathode exhibited high power/energy density and long cycling life.