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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]

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]

Self‐healing and flexibility are significant for many emerging applications of secondary batteries, which have attracted broad attention. Herein, a self‐healing flexible quasi‐solid Zn‐ion battery composing of flexible all‐in‐one cathode (VS2 nanosheets growing on carbon cloth) and anode (electrochemically deposited Zn nanowires), and a self‐healing hydrogel electrolyte, is presented. The free‐standing all‐in‐one electrodes enable a high capacity and robust structure during flexible transformation of the battery, and the hydrogel electrolyte possesses a good self‐healing performance. The presented battery remains as a high retention potential even after healing from being cut into six pieces. When bending at 60°, 90°, and 180°, the battery capacities remain 124, 125, and 114 mAh g−1, respectively, cycling at a current density of 50 mA g−1. Moreover, after cutting and healing twice, the battery still delivers a stable capacity, indicating a potential use of self‐healing and wearable electronics. [ABSTRACT FROM AUTHOR]

Magnesium batteries have been considered promising candidates for next‐generation energy storage systems owing to their high energy density, good safety without dendrite formation, and low cost of magnesium resources. However, high‐performance cathodes with stable capacity, good conductivity, and fast ions transport are needed, since many conventional cathodes possess a low performance and poor preparation controllability. Herein, a liquid‐driven coaxial flow focusing (LDCFF) approach for preparing a novel microcapsule system with controllable size, high loading, and stable magnesium‐storage performance is presented. Taking the MoS2‐infilled microcapsule as a case study, the magnesium battery cathode based on the microcapsules displays a capacity of 100 mAh g−1 after 100 cycles. High capacity retention is achieved at both low and high temperatures of −10, ‒5, and 45 °C, and a stable rate‐performance is also obtained. The influences of the liquid flow rates on the size and shell thickness of the microcapsules are investigated; and electron and ion diffusion properties are also studied by first‐principle calculations. The presented LDCFF method is quite general, and the high performance of the microcapsules enables them to find broad applications for making emerging energy‐storage materials and secondary battery systems. [ABSTRACT FROM AUTHOR]

Large volume expansion and structural breaking have been severe issues for emerging high‐performance secondary battery anodes. Herein, a novel microcapsule anode filled with tin (Sn) nanoflowers is presented, which is prepared through in situ interface polymerization of an oil‐in‐water emulsion system. The carbon shell of the microcapsules reduces the pulverization of the encapsulated Sn, and the voids inside the capsules provide efficient spaces for the volume change of Sn during lithiation–delithiation. The Sn‐filled microcapsules exhibit a high rate performance with a capacity decay rate as low as 0.38%, even after three rounds of repeated tests, and a stable capacity of 800 mAh g−1 after 200 cycles at 380 mA g−1. In addition, the electron transfer kinetics and Li‐ion diffusion are investigated, which indicate that the microcapsule system enables a good environment for both electron and ion transfer. [ABSTRACT FROM AUTHOR]

Current high‐energy‐density secondary battery electrodes have several issues, in major part due to mechanical instabilities. Herein, a novel, mechanically robust anode is presented, which consists of a leaf‐shaped architecture with high lithium‐storage performance. As a demonstrative example, a leaf‐shaped tin dioxide (SnO2) anode is prepared through a templated layer‐by‐layer approach. The robust mechanical properties of the SnO2 anode are demonstrated through density functional theory (DFT) in which principle stress caused by lithiation is calculated. Real‐time lithiation is observed using in situ transmission electron microscopy (TEM) technology. The presented anode shows a stable capacity of 760 mAh g−1 after 200 cycles at 0.2 C, and a high capacity retention of 99% is achieved after three rounds of measurements. [ABSTRACT FROM AUTHOR]