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Efficient synthesis of transition metal hydroxides on conductive substrate is essential for enhancing their merits in industrialization of energy storage field. However, most of the synthetic routes at present mainly rely on traditional bottom-up method, which involves tedious steps, time-consuming treatments, or additional alkaline media, and is unfavorable for high-efficiency production. Herein, we present a facile, ultrafast and general avenue to synthesize transition metal hydroxides on carbon substrate within 13 s by Joule-heating method. With high reaction kinetics caused by the instantaneous high temperature, seven kinds of transition metal-layered hydroxides (TM-LDHs) are formed on carbon cloth. Therein, the fastest synthesis rate reaches ~ 0.46 cm2 s−1. Density functional theory calculations further demonstrate the nucleation energy barriers and potential mechanism for the formation of metal-based hydroxides on carbon substrates. This efficient approach avoids the use of extra agents, multiple steps, and long production time and endows the LDHs@carbon cloth with outstanding flexibility and machinability, showing practical advantages in both common and micro-zinc ion-based energy storage devices. To prove its utility, as a cathode in rechargeable aqueous alkaline Zn (micro-) battery, the NiCo LDH@carbon cloth exhibits a high energy density, superior to most transition metal LDH materials reported so far.

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hybrid perovskite solar cells (PVSCs) have attracted more and more attention because of the decent properties of perovskites such as high absorption coefficient, tunable optical bandgap, long carrier lifetime, high mobility and long diffusion length. PVSCs have achieved great improvements with power conversion efficiency now reaching certified 25.2%, which showed huge potential for future commercialization. [1][2][3][4][5][6][7] State-ofthe-art PVSCs use solution-processed perovskite films to absorb incident light. The halide perovskite absorbers are generally regarded as soft ionic solids, which are prone to contain defects in polycrystalline films (e.g., vacancies, interstitials, and cation and antisite substitutions). [8] The widely used one-step spin-casting procedure represents the simplest solution process, in which stoichiometric organic and metal halide precursors are mixed in organic solvents and transformed into intermediate perovskite crystalline thin films by centrifugal force and solvent evaporation. Such a simple deposition route has cost advantages and potential of device scaling up, but a large number of defects will inevitably form during the spin-casting process. For example, the spin-casting process may cause the formation of some anomalous perovskite clusters which are easy to be decomposed, resulting in the formation of ionic defects such as iodide vacancies or uncoordinated lead/halide ions. The presence of such defects in perovskites has commonly been recognized as fatal, such that the perovskite properties (e.g., conductivity, free charge mobility, and charge lifetime) are significantly decreased. Defects will also cause serious carrier recombination including radiative and nonradiative recombination, which have been demonstrated to be the main reason for energy loss in perovskite photovoltaic devices and are detrimental to the carrier lifetime of perovskite film, the performance and stability of PVSCs. [9] Efficient control and engineering of defects distributed in light-absorbing semiconductor materials have been proven to be an effective way to accelerate the development of high-performance perovskite solar cells. [10] To reduce the defects and eliminate the recombination, researchers have Perovskite solar cells (PVSCs) have achieved excellent power conversion efficiency (PCE) but still suffer from instability issues. Defect passivation is an important route to simultaneously increase the efficiency and stability ofPVSCs. Here, a strategy of incorporating silica oligomer in perovskite films for surface and grain boundary defect passivation is reported. Silica oligomer passivation agent (PA) is in situ formed through hydrolysis and condensation reaction of tetraethyl orthosilicate additive in perovskite precursor. The passivation mechanism is elucidated by density functional theory calculation, revealing stable chelating interaction and hydrogen bond interaction between PA and perovskite. Spectroscopic and electrical characterizations demonstrate that silica oligomer can enlarge grain si...