The weak van der Waals interactions enable ion‐intercalation‐type hosts to be ideal pseudocapacitive materials for energy storage. Here, a methodology for the preparation of hydrated vanadium dioxide nanoribbon (HVO) with moderate transport pathways is proposed. Out of the ordinary, the intercalation pseudocapacitive reaction mechanism is discovered for HVO, which powers high‐rate capacitive charge storage compared with the battery‐type intercalation reaction. The main factor is that the defective crystalline structure provides suitable ambient spacing for rapidly accommodating and transporting cations. As a result, the HVO delivers a fast Zn2+ ion diffusion coefficient and a low Zn2+ diffusion barrier. The electrochemical results with intercalation pseudocapacitance demonstrate a high reversible capacity of 396 mAh g−1 at 0.05 A g−1, and even maintain 88 mAh g−1 at a high current density of 50 A g−1.
The zinc (Zn)‐ion battery has attracted much attention due to its high safety and environmental protection. At present, the critical issues of the generation of dendrites and the accumulation of dead Zn on the surface will lead to a sharp decline of the battery life. Zn dendrites can be inhibited to some extent by constructing an interface protective coating. However, the existing rigid coating method cannot maintain conformal contact with Zn due to the volume change of Zn deposition and will cause fracture irreversibly during the cycle. Here, a highly self‐adaptable poly(dimethylsiloxane) (PDMS)/TiO2−x coating is developed that can dynamically adapt to volume changes and inhibit dendrites growth. PDMS has high dynamic and self‐adaptability due to the crosslinking of the B–O bond. In addition, the rapid and uniform transfer of Zn2+ is induced by the oxygen‐vacancy‐rich TiO2−x. The assembled cells still achieve 99.6% coulombic efficiency after 700 cycles at a current density of 10 mA cm−2. The adaptive interface coating constructed provides a sufficient guarantee for the stable operation of the Zn anode.
Mn-based cathodes are admittedly the most promising candidate to achieve the practical applications of aqueous zinc-ion batteries because of the high operating voltage and economic benefit. However, the design of Mn-based cathodes still remains challenging because of the vulnerable chemical architecture and strong electrostatic interaction that lead to the inferior reaction kinetics and rapid capacity decay. These intrinsic drawbacks need to be fundamentally addressed by rationally decorating the crystal structure. Herein, an oxygen-defective Mnbased cathode (Oc u -Mn 2 O 3 ) is designed via a doping low-valence Cu-ion strategy. The oxygen defect can modify the internal electric field of the material and enhance the substantial electrostatic stability by compensating for the nonzero dipole moment. With the merits of oxygen deficiency, the Oc u -Mn 2 O 3 electrode exhibits the significant diffusion coefficient in the range from 1 × 10 −6 to 1 × 10 −8 , and good rate performance. In addition, the Oc u -Mn 2 O 3 maintains the highly reversible cyclic stability with the capacity retention of 88% over 600 cycles. The charge storage mechanism is explored as well, illustrating that the oxygen defects can improve the electrochemical active sites of H + insertion, achieving a better charge-storage capacity than Mn 2 O 3 .
The development and application of aqueous zinc-ion batteries still face some obstacles, such as dendrite growth and side reactions triggered by active water. Here, we constructed PVA@SR-ZnMoO4 multifunctional coating on...
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