Due to an ever-increasing demand for electronic devices, rechargeable batteries are attractive for energy storage systems. A novel rechargeable aluminum-ion battery based on Al³⁺ intercalation and deintercalation is fabricated with Ni₃S₂/graphene microflakes composite as cathode material and high-purity Al foil as anode. This kind of aluminum-ion battery comprises of an electrolyte containing AlCl₃ in an ionic liquid of 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl). Galvanostatic charge/discharge measurements have been performed in a voltage range of 0.1–2.0 V versus Al/AlCl₄ ⁻. An initial discharge specific capacity of 350 mA h g⁻¹ at a current density of 100 mA g⁻¹ is achieved, and the discharge capacity remains over 60 mA h g⁻¹ and coulombic efficiency of 99% after 100 cycles. Typically, for the current density at 200 mA g⁻¹, the initial charge and discharge capacities are 300 and 235 mA h g⁻¹, respectively. More importantly, it should be emphasized that the battery has a high discharge voltage plateau (≈1.0 V vs Al/AlCl₄ ⁻). These meaningful results represent a significant step forward in the development of aluminum-ion batteries.

Producing graphene through the electrochemical reduction of CO₂ remains a great challenge, which requires precise control of the reaction kinetics, such as diffusivities of multiple ions, solubility of various gases, and the nucleation/growth of carbon on a surface. Here, graphene was successfully created from the greenhouse gas CO₂ using molten salts. The results showed that CO₂ could be effectively fixed by oxygen ions in CaCl₂–NaCl–CaO melts to form carbonate ions, and subsequently electrochemically split into graphene on a stainless steel cathode; O₂ gas was produced at the RuO₂–TiO₂ inert anode. The formation of graphene in this manner can be ascribed to the catalysis of active Fe, Ni, and Cu atoms at the surface of the cathode and the microexplosion effect through evolution of CO in between graphite layers. This finding may lead to a new generation of proceedures for the synthesis of high value-added products from CO₂, which may also contribute to the establishment of a low-carbon and sustainable world.

The capture and electrochemical conversion of CO₂ in molten LiCl–Li₂CO₃ salt is proposed. By using an inert platinum anode and a tungsten cathode, the CO₃²⁻ could be easily converted into carbon and oxygen gas, as well as O²⁻. The released O²⁻ was responsible for the further capture of CO₂. Also, CO₂ could be effectively absorbed in such chloride melts with a low content of oxygen ion dissolved. In addition, the produced carbon displayed good performance as a negative electrode material for Li-ion batteries, suggesting that the process is an environmentally friendly way to convert CO₂ into energy-storage materials.

Hollow α-Fe₂O₃ nanospheres are synthesized by a carbon-template method. The open channels and tiny particles present within the hollow nanospheres facilitate the penetration of the electrolyte, efficiently reducing the diffusion length for both Na ions and electrons and tolerating volume expansion and particle pulverization. A high discharge capacity of 837.3 mAh g⁻¹ is obtained and obvious voltage plateaus can be observed during the charge and discharge process.