Petroleum-Pitch-Based Carbon Nanocages Encapsulated Few-Layer MoS<sub>2</sub> with S Vacancies for a High-Performance Sodium-Ion Battery
Yan Zhao, Yao Cong, Hui Ning, Yiwen Li, Hao Yang, Zhenmei Jiao, Dewen Song, Yongzhe Li, Qingshan Zhao, Mingbo Wu
Abstract
Molybdenum disulfide (MoS 2 ), one of the promising anode materials for high-energy-density sodium-ion batteries (SIBs), is subjected to poor electronic conductivity and severe volume expansion during the charge–discharge cycle. Herein, cage-like carbon was prepared from petroleum pitch to composite with few-layer MoS 2 as MoS 2 /C anodes for SIBs, giving an excellent capacitive performance (89.18% at 1.4 mV s –1 ) and nearly 100% capacity retention after 300 cycles at 1 A g –1 . The unique cage-like structures relieve the volume expansion of MoS 2 during the charge–discharge cycles. Meanwhile, MoS 2 has an expanded interlayer distance (0.685 nm) and abundant S vacancies, affording rich active sites for the adsorption diffusion of sodium ions. This work provides a convenient method to solve the inherent defects of MoS 2 by introducing cage-like carbon from petroleum pitch.