Ternary
Hybrid Material for High-Performance Lithium–Sulfur
Battery
- Publication date
- 2015
- Publisher
Abstract
The rechargeable lithium–sulfur
battery is a promising option
for energy storage applications because of its low cost and high energy
density. The electrochemical performance of the sulfur cathode, however,
is substantially compromised because of fast capacity decay caused
by polysulfide dissolution/shuttling and low specific capacity caused
by the poor electrical conductivities of the active materials. Herein
we demonstrate a novel strategy to address these two problems by designing
and synthesizing a carbon nanotube (CNT)/NiFe<sub>2</sub>O<sub>4</sub>–S ternary hybrid material structure. In this unique material
architecture, each component synergistically serves a specific purpose:
The porous CNT network provides fast electron conduction paths and
structural stability. The NiFe<sub>2</sub>O<sub>4</sub> nanosheets
afford strong binding sites for trapping polysulfide intermediates.
The fine S nanoparticles well-distributed on the CNT/NiFe<sub>2</sub>O<sub>4</sub> scaffold facilitate fast Li<sup>+</sup> storage and
release for energy delivery. The hybrid material exhibits balanced
high performance with respect to specific capacity, rate capability,
and cycling stability with outstandingly high Coulombic efficiency.
Reversible specific capacities of 1350 and 900 mAh g<sup>–1</sup> are achieved at rates of 0.1 and 1 C respectively, together with
an unprecedented cycling stability of ∼0.009% capacity decay
per cycle over more than 500 cycles