Petroleum-Pitch-Based Carbon Nanocages Encapsulated Few-Layer MoS2 with S Vacancies for a High-Performance Sodium-Ion Battery

Molybdenum disulfide (MoS2), 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 MoS2 as MoS2/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 MoS2 during the charge–discharge cycles. Meanwhile, MoS2 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 MoS2 by introducing cage-like carbon from petroleum pitch.