Anchoring perovskite-Type FeMnO3 microspheres on CNT conductive networks via electrostatic self-assembly for high-performance lithium-ion capacitors

Lithium-ion capacitors (LICs) are emerging energy storage devices that integrate the high energy density of lithium-ion batteries with the high-power density of supercapacitors. However, their practical performance is severely limited by the sluggish reaction kinetic for battery-type anodes. To address this issue, we propose an electrostatic self-assembly strategy for fabricating perovskite-type FeMnO3 microspheres anchored within the carbon nanotube conductive network (FeMnO3-CNTCN) as the anode materials for LICs. In the well-interconnected 3D construction, FeMnO3 microspheres with multi-step redox reaction can provide abundant active sites for the lithium storage, while highly conductive and flexible CNT substrate ensures fast lithium-ion transport and electron transfer. Benefiting from the synergistic interplay between two components, the FeMnO3-CNTCN anode exhibits the splendid cyclability and rate performance. Furthermore, the entire LIC with FeMnO3-CNTCN anode delivers a superior energy density of 163 Wh kg−1 at a power density of 245 W kg−1, along with a capacity retention of 83% after 10,000 cycles. These results demonstrate the promising prospect of FeMnO3-CNTCN in high-performance LICs, and the proposed electrostatic self-assembly strategy opens up a chance for the facile synthesis of the composite materials in advanced energy storage.