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Safe and high‐performance secondary batteries using for all‐climate conditions with different temperatures are highly required. Here, we develop a three‐dimensional ball cactus‐like MgV2O4 as cathode material for magnesium‐ion (Mg‐ion) batteries. After cycling 300 times, the capacity maintains 111.7 mAh g−1, while Coulombic efficiency stabilizes at about 100 %. Under temperatures of 45 °C and −5 °C, the capacities remain stable after 200 cycles. After three rounds of rate‐performance tests, the capacity keeps quite stable. It is ascribed to the ball cactus‐like morphology buffers the volumetric change during Mg2+ insertion/extraction, and provides sufficient pathways for ion diffusion, which has been verified by constant‐current intermittent titration technology. It is believed that the good performance enables the Mg‐ion batteries to have a all‐climate capability. [ABSTRACT FROM AUTHOR]

Anhui Provincial Engineering Laboratory for Engineering appropriate cathode materials is significant for the development of high‐performance aluminum‐ion (Al‐ion) batteries. Here, a pyramidal metal–organic frameworks (MOFs)‐derived FeP@CoP composite was developed as cathode, which exhibits good stability and high capacity. FeP@CoP cathode maintains a high capacity of 168 mAh g−1 after 200 cycles, and displays a stable rate‐performance at both room and low temperatures of −10 °C. After three rounds of rate‐performance cycling, the FeP@CoP composite recovers 178.2 mAh g−1 at 0.3 A g−1. Moreover, density functional theory (DFT) calculations verify improved electron‐transfer kinetics with narrowed band gap and enhanced density of states. These findings inspire a broad set of studies on MOFs‐derived composites for high‐performance secondary batteries. [ABSTRACT FROM AUTHOR]

A foldable battery with high flexibility provides great potential in various wearable electronic devices for health and fitness tracking, chronic disease management, performance monitoring, navigation tracking, and portable gears for soldiers. We report a highly flexible, self‐healing Zn‐ion battery with a free‐standing cathode that is composed of a 3D gear‐like NH4V4O10@C composite on carbon paper. The battery retained a capacity of up to 102.4 mAh g−1 even after being folded 60 times with a high angle of 180°. An aqueous hydrogel consisting polyvinyl alcohol, glycerin and Zn(CF3SO3)2 was used as electrolyte, which showed as high as 580 % tensile strain under a loading weight of 78 N. The battery exhibited a better capacity retention of over 100 mAh g−1 and Coulombic efficiency of over 99.8 % after cutting and twisting to 90°, thereby indicating a great self‐healing performance. The gear‐like geometry greatly improved the volume accommodation due to the increased interval space between the blades and the outward configuration. Meanwhile the Zn2+ ionic conductivity was improved by rapid re‐binding of many existing hydroxy groups from the electrolyte and the enhanced contact surface area and diffusion route from the cathode material. The highly flexible, safe aqueous Zn‐ion battery opens a practical way to power various carry‐on electronics under mechanical agitation. [ABSTRACT FROM AUTHOR]

The shuttling behavior and slow conversion kinetics of the intermediate lithium polysulfides are the severe obstacles for the application of lithium‐sulfur (Li‐S) batteries over a wide temperature range. Here, an engineered lamellar yolk–shell structure of In2O3@void@carbon for the Li‐S battery cathode is developed for the first time to construct a powerful barrier that effectively inhibits the shuttling of polysulfides. On the basis of the unique nanochannel‐containing morphology, the continuous kinetic transformation of sulfur and polysulfides is confined in a stable framework, which is demonstrated by using X‐ray nanotomography. The constructed Li‐S battery exhibits a high cycling capability over 1000 cycles at 1.0 C with a capacity decay rate as low as 0.038% per cycle, good rate performance, and temperature tolerance at −10, 25, and 50 °C. A nondestructive in situ monitoring method of the interfacial reaction resistance in different cycling stages is proposed, which provides a new analysis perspective for the development of emerging electrochemical energy‐storage systems. [ABSTRACT FROM AUTHOR]

Self‐healing secondary batteries have attracted great attention for constructing stable energy‐storage systems. Herein, a novel self‐healing rechargeable magnesium battery cathode is developed using self‐healing microcapsules in a vanadium pentoxide microflower‐based cathode. The microcapsules are prepared through a microfluidic approach. The core of the microcapsule contains a conductive hydrogel and carbon nanospheres, and the shell composes of a UV‐curved polymer. When the self‐healing Mg battery cathode cracks, the microcapsules break and release the core into the cracks, rebuilding the pathways for the electron transport and enabling a stable electrochemical performance. The presented cathode displays a good capacity of 105 mAh g−1 after 500 cycles at 100 mA g−1 and it delivers a stable capacity of 98.3 mAh g−1 after long‐term cycling 1000 times at 200 mA g−1. A recoverable rate‐performance and a good temperature tolerance are also achieved. It is expected that the general preparation approach of the self‐healing microcapsules and the long‐term stable Mg battery will find broad applications for developing many emerging energy‐storage systems. [ABSTRACT FROM AUTHOR]

Chemically and mechanically robust sulfur (S) cathodes are highly significant for high‐performance lithium‐sulfur (Li‐S) batteries. Herein, a novel 3D hydrogel@S composite as binder‐free high‐performance cathode is presented, which consists of a 3D conductive hydrogel polyaniline (PAN) scaffold coated with dense S particles. The 3D PAN@S composite exhibits polysulfides‐adsorptive performance, suitable structure for accommodating the volume change of S upon lithiation, and improved overall conductivity of the electrode. After cycling for 100 times at 0.2 C, the binder‐free 3D PAN@S composite shows a capacity of 816 mAh g−1, along with a Coulombic efficiency as high as 99.9%. A good electrochemical performance is also achieved when cycling at a high temperature of 50 °C. In addition, the adsorptive effect of PAN towards polysulfides is demonstrated through density functional theory calculations on the adsorption energies. [ABSTRACT FROM AUTHOR]