Fabrication of Mesoporous Carbon CMK-3 Modified Co0.9Cu0.1Si Alloy for Electrochemical Hydrogen Storage

Abstract

Mechanical alloying is used to prepare the Co[Formula: see text]Cu[Formula: see text]Si alloy. Mesoporous silicon SBA-15 is employed as the template to synthesize mesoporous carbon CMK-3. For the purpose of improving the electrochemical properties of Co[Formula: see text]Cu[Formula: see text]Si alloy, Co[Formula: see text]Cu[Formula: see text] CMK-3 ([Formula: see text], 6%, 9% and 12% mass fraction) alloys are fabricated via ball-milling. As the negative electrodes of Ni–MH batteries, the discharge capacities of alloys are tested by the LAND CT2001A tester and three-electrode system. Finally, the composite alloys show different properties for hydrogen storage. A maximum discharge capacity (558.7[Formula: see text]mAh/g) is achieved for Co[Formula: see text]Cu[Formula: see text] CMK-3 electrode. Superfluous CMK-3 is not beneficial to enhance the discharge capacity of Co[Formula: see text]Cu[Formula: see text]Si alloy. Moreover, Co[Formula: see text]Cu[Formula: see text] CMK-3 electrodes exhibit better corrosion and oxidation resistance, which leads to higher capacity retention for CMK-3/Co[Formula: see text]Cu[Formula: see text]Si composites. The comparative studies on HRD and kinetic properties of Co[Formula: see text]Cu[Formula: see text]Si and Co[Formula: see text]Cu[Formula: see text] CMK-3 are also conducted. The [Formula: see text] of Co[Formula: see text]Cu[Formula: see text]Si alloy reduces and [Formula: see text] increases after doping of CMK-3. The special structural characteristics and higher conductivity of CMK-3 can offer more electrochemical active sites and accelerate hydrogen diffusion. Accordingly, the electrochemical activity and kinetic properties are enhanced for CMK-3/Co[Formula: see text]Cu[Formula: see text]Si composites.