Calcium-ion batteries (CIBs) are considered as promising alternatives in large-scale energy storage due to their divalent electron redox properties, low cost, and high volumetric/gravimetric capacity. However, the high charge density of Ca 2+ contributes to strong electrostatic interaction between divalent Ca 2+ and hosting lattice, leading to sluggish kinetics and poor rate performance. Here, in situ formed poly(anthraquinonyl sulfide) (PAQS)@CNT composite is reported as nonaqueous calcium-ion battery cathode. The enolization redox chemistry of organics has fast redox kinetics, and the introduction of carbon nanotube (CNT) accelerates electron transportation, which contributes to fast ionic diffusion. As the conductivity of the PAQS is enhanced by the increasing content of CNT, the voltage gap is significantly reduced. The PAQS@CNT electrode exhibits specific capacity (116 mAh g −1 at 0.05 A g −1 ), high rate capacity (60 mAh g −1 at 4 A g −1 ), and an initial capacity of 82 mAh g −1 at 1 A g −1 (83% capacity retention after 500 cycles). The electrochemical mechanism is proved to be that the PAQS undergoes reduction reaction of their carbonyl bond during discharge and becomes coordinated by Ca 2+ and Ca(TFSI) + species. Computational simulation also suggests that the construction of Ca 2+ and Ca(TFSI) + co-intercalation in the PAQS is the most reasonable pathway.

Rechargeable zinc‐ion batteries (ZIBs), which adopt mild aqueous electrolytes with high power density and safety, have received significant interest. As the most widely used cathode material for ZIBs, manganese‐based oxide has poor rate performance owing to its low electronic conductivity and slow ion diffusion kinetics. In this study, using the synergistic regulation strategy of defect engineering and atomic composition tuning, a mesoporous Al0.35Mn2.52O4 with an ultrahigh surface area (up to 82 m2 g−1) is fabricated through Al substitution in the Mn3O4, followed by an Al‐selective leaching process. During the entire process, numerous defects are obtained in the spinel structure by removing ≈30% of the Al cations. Al substitution can improve the material conductivity, while cation defects can weaken the electrostatic effect and promote ion diffusion ability. Therefore, the Al0.35Mn2.52O4 cathode of ZIBs exhibits a high reversible capacity of 302 mAh g−1 at a current density of 100 mA g−1. Furthermore, the reversible capacity remains at 147 mAh g−1 after 1000 cycles at a current density of 1500 mA g−1. This synergistic regulation of atomic composition tuning and defect engineering provides a new perspective for improving the performance of electrode materials in ZIBs.

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Unique Li4Ti5O12/TiO2 multilayer arrays from a substrate-free method demonstrate advanced surface lithium storage capability.

It described a control system of 100kV high voltage power supply. It used PC control and monitor the power modules via fiber optic. By testing, proved the control system is a good isolation and provides stability control system. By this way, we can remote control the power modules.