Construction of anode materials for NiSe-based high energy density lithium-ion capacitors

Abstract

Nickel selenide has been extensively used in energy storage applications because of its easily adjustable morphology, high theoretical specific capacity, abundant reserves, and low price. It is an idealized anode material for lithium-ion capacitors (LICs). However, the volume effect and ion transport efficiency during the transmission process are low, resulting in improved cycle and rate performance. In view of the above problems, NiSe/carbon nanotube@polyaniline (NiSe/CNT@PANI) nanocomposites are prepared by the hydrothermal method and in-situ polymerization. After 100 cycles at 0.1 A·g−1, the charge specific capacity is 529.3 mAh·g−1. After 300 cycles at 1 A·g−1 and 2 A·g−1, the charge specific capacity is still 271.8 mAh·g−1 and 173.5 mAh·g−1, respectively. Furthermore, the constructed NiSe/CNT@PANI//AC LICs have an initial reversible capacity of 50.9 mAh·g−1 at 0.1 A·g−1, a cycle retention rate of 56.5% after 3000 cycles at 1 A·g−1. When the power density is 199.5 W·kg−1, the energy density is 91.7 Wh·kg−1, and the energy density reaches 53.1 Wh·kg−1 at a high power density of 1995.4 W·kg−1. These results indicate that NiSe/CNT@PANI composites have broad application prospects in LICs.