Developing efficient, stable, and low-cost catalysts for oxygen evolution reaction (OER) is highly desired in water splitting and metal−air batteries. Transition metal−organic frameworks (MOFs) have emerged as promising catalysts and have been intensively investigated especially due to their tunable crystalline structure. Unlike traditional strategies of tuning the morphology of well-crystalline MOFs, low-crystalline bimetallic MOFs are constructed via inducing exotic metal ions, and the formation process is revealed by experimental and theoretical methods. The lowcrystalline bimetallic MOFs exhibit rich active sites due to local crystallinity and long-range disorder and deliver a small overpotential of 260 mV at 10 mA cm −2 , a low Tafel slope of 35 mV dec −1 , and a high Faradaic efficiency of 99.5% as oxygen evolution elecctrocatalysts. The work opens up a new avenue for the development of highly efficient earth-abundant catalysts in frontier potential applications.

The aqueous zinc ion batteries (ZIBs) composed of inexpensive zinc anode and nontoxic aqueous electrolyte are attractive candidates for large-scale energy storage applications. However, their development is limited by cathode materials, which often deliver inferior rate capability and restricted cycle life. Herein, the VO 2 nanorods show significant electrochemical performance when used as an intercalation cathode for aqueous ZIBs. Specifically, the VO 2 nanorods display high initial capacity of 325.6 mAh g −1 at 0.05 A g −1 , good rate capability, and excellent cycling stability of 5000 cycles at 3.0 A g −1 . Furthermore, the VO 2 unit cell expands in a, b, and c directions sequentially during the discharge process and contracts back reversibly during the charge process, and the zinc storage mechanism is revealed to be a highly reversible single-phase reaction by operando techniques and corresponding qualitative analyses. Our work not only opens a new door to the practical application of VO 2 in ZIB systems but also broadens the horizon in understanding the electrochemical behavior of rechargeable ZIBs.

3 ) and better plating/stripping reversibility than Mg, Ca, and Al. [3] In addition, as an earth-abundant metal, the price of Zn is only ≈4% of Li. [4] Therefore, aqueous zinc-ion batteries (AZIBs) have ushered in an unprecedented development in the past few years. Considerable efforts have been made to further improve the reversibility of Zn plating/stripping. [5,6] At the same time, it should be noted that the dendrite growth caused by uneven Zn plating can not only reduce the reversibility, but also directly cause a short circuit after penetrating the separator, seriously limiting the life span of AZIBs. [7,8] Regulating Zn plating behavior at electrolyte-anode interface to realize smooth Zn deposition is necessary to stabilize Zn anode. [9,10] One of the main methods is electrolyte regulation, [11] including designing unique electrolyte systems, [12][13][14] using electrolyte additives, [15,16] developing gel electrolytes, [17] etc. Another key strategy is Zn anode surface modification, namely constructing artificial interface layer on Zn foil. Recently, various materials including organics (polyamide, [18] polyacrylonitrile, [19] poly(vinyl butyral), [20] etc.) and inorganics (TiO 2 , [21] CaCO 3 , [22] ZrO 2 , [23] Al 2 O 3 , [24] etc.) have been constructed as protective interface layers by doctor blading, spin coating, or atomic layer deposition (ALD) methods. However, they face some practical limitations, including difficulty in controlling consistency of layer composition/structure and thickness, or inability to accommodate easy mass production. For example, additional binders are required for doctor-blading Uneven distribution of electric fields at the electrolyte-anode interface and associated Zn dendrite growth is one of the most critical barriers that limit the life span of aqueous zinc-ion batteries. Herein, new-type Zn-A-O (A = Si, Ti) interface layers with thin and uniform thickness, porosity, and hydrophilicity properties are developed to realize homogeneous and smooth Zn plating. For ZnSiO 3 nanosheet arrays on Zn foil (Zn@ZSO), their formation follows an "etching-nucleation-growth" mechanism that is confirmed by a well-designed Zn-island-based identical-location microscopy method, the geometric area of which is up to 1000 cm 2 in one-pot synthesis based on a lowtemperature wet-chemical method. Guided by the structural advantages of the ZSO layer, the Zn 2+ flux gets equalized. Besides ultralow polarization, the life spans of symmetric cells and full cells coupled with a high-mass-loading K 0.27 MnO 2 •0.54H 2 O (8 mg cm −2 ) cathode, are increased by 3-7 times with the Zn@ZSO anode. Moreover, the large-scale preparation of Zn@ZSO foil contributes to a 0.5 Ah multilayer pouch cell with high performance, further confirming its prospects for practical application.

Titanium oxynitride mesoporous nanowires (Ti(O,N)-MP-NWs) composed of iso-oriented interconnected nanocrystals with [100] preferred orientation and tunable O/N ratios are synthesized and exhibit remarkable pseudocapacitive behavior for ultrahigh-rate sodium ion hybrid capacitor.

Conversion-type anodes with multielectron reactions are beneficial for achieving a high capacity in sodium-ion batteries. Enhancing the electron/ion conductivity and structural stability are two key challenges in the development of high-performance sodium storage. Herein, a novel multidimensionally assembled nanoarchitecture is presented, which consists of V O nanoparticles embedded in amorphous carbon nanotubes that are then coassembled within a reduced graphene oxide (rGO) network, this materials is denoted V O ⊂C-NTs⊂rGO. The selective insertion and multiphase conversion mechanism of V O in sodium-ion storage is systematically demonstrated for the first time. Importantly, the naturally integrated advantages of each subunit synergistically provide a robust structure and rapid electron/ion transport, as confirmed by in situ and ex situ transmission electron microscopy experiments and kinetic analysis. Benefiting from the synergistic effects, the V O ⊂C-NTs⊂rGO anode delivers an ultralong cycle life (72.3% at 5 A g after 15 000 cycles) and an ultrahigh rate capability (165 mAh g at 20 A g , ≈30 s per charge/discharge). The synergistic design of the multidimensionally assembled nanoarchitecture produces superior advantages in energy storage.