关键词: 溶解氧, 氧还原反应, 碳纤维, 镁合金, 海水电池, 准电容

Abstract: A new concept of seawater battery with electrochemical capacitance (SWB-EC) has been proposed using carbon fibre brush (CFB) as the cathode material, and three testing prototypes have been made accordingly. The discharge performances of the CFB before- and after-oxidation and Mg alloy sacrifice anode were studied by cyclic voltammetry and constant current discharge tests under steady state conditions. Results show that the oxidized CFB exhibits the pseudo-capacitive characteristic and its activity of oxygen reduction reaction (ORR) in stirred seawater highly increases, comparing with the non-oxidized CFB. The open circuit potential of Mg alloy sacrifice anode is -1.74 V, having the advantages of high working potential and uniform dissolution. The consecutive marine discharge test is conducted for prototypes made of the oxidized CFB cathode and Mg alloy sacrifice anode. The preliminary data collected in two months reveals that comparing with the commercial seawater battery—SWB1200, the home-made SWB-EC achieves a higher volume specific power density.

Key words: dissolved oxygen；oxygen reduction reaction (ORR), carbon fibre, Mg alloy；seawater battery；pseudo-capacitance