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 MoS2/C19H42N+ (CTAB) superstructure can be rationally designed as a stable and high-rate cathode. Incorporation of soft organic CTAB into a rigid MoS2 host forming the superlattice structure not only effectively initiates and smooths Zn2+ transport paths by significantly expanding the MoS2 interlayer spacing (1.0 nm) but also endows structural stability to accommodate Zn2+ storage with expansion along the MoS2 in-plane, while synchronous shrinkage along the superlattice interlayer achieves volume self-regulation of the whole cathode, as evidenced by in situ synchrotron X-ray diffraction and substantial ex situ characterizations. Consequently, the optimized superlattice cathode delivers high-rate performance, long-term cycling stability (∼92.8% capacity retention at 10 A g–1 after 2100 cycles), and favorable flexibility in a pouch cell. Moreover, a decent areal capacity (0.87 mAh cm–2) is achieved even after a 10-fold increase of loading mass (∼11.5 mg cm–2), which is of great significance for practical applications. This work highlights the design of multifunctional superlattice electrodes for high-performance aqueous batteries.

urgent strategies worldwide. [1] Rechargeable lithium-ion batteries have achieved great success during the last 40 years, while they gradually display certain limitations in further large-scale applications, such as high cost, uneven geological distribution and short supplies of lithium resources (0.0017 wt%) around the world. As alternative energy storage sources, sodium ion batteries (SIBs) and potassium ion batteries (PIBs) have recently attracted tremendous interest owing to their natural abundance, low cost and environmental friendliness. Despite having a similar abundance with sodium (sodium and potassium represent 2.36 and 2.09 wt% in the Earth's crust, respectively), potassium presents some specific advantages. K + /K exhibit a lower standard redox potential of −2.93 V (vs E°) compared with that of Na + /Na (−2.71 V vs E°), implying a higher working voltage and energy density of PIBs. [2] Moreover, potassium ions have much better conductivity and relatively lower desolvation energy in organic solvents. [3] These merits of potassium make it a promising low-cost candidate for high-energy and power density energy storage applications.The progress of PIBs mainly follows the development of electrode materials, especially considering the large-size of Metallic bismuth (Bi) has been widely explored as remarkable anode material in alkali-ion batteries due to its high gravimetric/volumetric capacity. However, the huge volume expansion up to ≈406% from Bi to full potassiation phase K 3 Bi, inducing the slow kinetics and poor cycling stability, hinders its implementation in potassium-ion batteries (PIBs). Here, facile strategy is developed to synthesize hierarchical bismuth nanodots/graphene (BiND/G) composites with ultrahigh-rate and durable potassium ion storage derived from an in situ spontaneous reduction of sodium bismuthate/graphene composites. The in situ formed ultrafine BiND (≈3 nm) confined in graphene layers can not only effectively accommodate the volume change during the alloying/dealloying process but can also provide high-speed channels for ionic transport to the highly active BiND. The BiND/G electrode provides a superior rate capability of 200 mA h g −1 at 10 A g −1 and an impressive reversible capacity of 213 mA h g −1 at 5 A g −1 after 500 cycles with almost no capacity decay. An operando synchrotron radiation-based X-ray diffraction reveals distinctively sharp multiphase transitions, suggesting its underlying operation mechanisms and superiority in potassium ion storage application.