Electrolytic calcium hexaboride for high capacity anode of aqueous primary batteries

Abstract

The use of lightweight elements/compounds and the employment of multi-electron reaction (MER) chemistry are two approaches used to develope high energy density materials for batteries. In this work, nanoscaled calcium hexaboride (CaB 6 ) was prepared in one-step by the electro-reduction of solid calcium borate (CaB 2 O 4 ) in molten CaCl 2 -NaCl. CaB 2 O 4 was synthesized by a simple co-precipitation method. It was revealed that the electrolytic CaB 6 delivers a specific capacity of 2400 mA h g À1 in 30%KOH solution though a multi-electron reaction mechanism. Its practical gravimetric energy is three times that of Zn. Decrease of particle size substantially improves both the electrochemical activity and discharge capacity of CaB 6 . The electrolysis of CaB 2 O 4 in molten salt provides a straightforward and sustainable way to prepare high-capacity CaB 6 using low-cost and environmentally friendly boron and calcium resources, which can be recycled from the used CaB 6 primary batteries.

Electrochemical reduction behavior of vitrified nuclear waste simulant in molten CaCl2

“…4b. This discrepancy has already been reported in papers on the electrochemical reduction of simulants 1 and 2 [7] and CaB2O4 [58]. The formation of SiB6 is also possible at a more negative potential than 0.9 V. To distinguish CaB6 and SiB6, further investigation is required.…”

A Convenient Electrochemical Method for Preparing Carbon Nanotubes Filled with Amorphous Boron

“…It has been widely recognized that boron obtained by electrolysis in molten salts was amorphous. [28][29][30][31] Therefore, the peak with the center at 187.6 eV was employed to fit the raw data. This confirms that C and B exist in the products.…”

Synthesis of Fe-Fe2B catalysts via solvothermal route for hydrogen generation by hydrolysis of NaBH4

“…Nanoparticles of metal borides of various crystallite size and shapes can be produced by self-propagating high-temperature synthesis [42], molten salt method [43], electrolysis method [44], chemical vapor deposition [45], carbothermal method [46], sol-gel [47][48], mechanochemical [49] and solvothermal methods [50]. However, solvothermal methods are preferred over the other methods due to their ability to produce nanoparticles of uniform shapes and sizes.…”