A Volume Self-Regulation MoS Superstructure Cathode for Stable and High Mass-Loaded Zn-Ion Storage.

Engineering multifunctional superstructure cathodes to conquer the critical issue of sluggish kinetics and large volume changes associated with divalent Zn-ion intercalation reactions is highly desirable for boosting practical Zn-ion battery applications. Herein, it is demonstrated that a MoS/CHN (CTAB) superstructure can be rationally designed as a stable and high-rate cathode. Incorporation of soft organic CTAB into a rigid MoS host forming the superlattice structure not only effectively initiates and smooths Zn transport paths by significantly expanding the MoS interlayer spacing (1.0 nm) but also endows structural stability to accommodate Zn storage with expansion along the MoS in-plane, while synchronous shrinkage along the superlattice interlayer achieves volume self-regulation of the whole cathode, as evidenced by synchrotron X-ray diffraction and substantial characterizations. Consequently, the optimized superlattice cathode delivers high-rate performance, long-term cycling stability (∼92.8% capacity retention at 10 A g after 2100 cycles), and favorable flexibility in a pouch cell. Moreover, a decent areal capacity (0.87 mAh cm) is achieved even after a 10-fold increase of loading mass (∼11.5 mg cm), which is of great significance for practical applications. This work highlights the design of multifunctional superlattice electrodes for high-performance aqueous batteries.