Development of Electrochemical Capacitors with Noble Metal Oxide-Coated Electrodes

本课题的研究目的是设计具有大拟电容的高多孔氧化膜电极，并使其能够在电动汽车上负载。采用以下两种方法制备了具有较大伪电容的ruo_2或iro_2基电极。浸涂法与SnO_2、TiO_2、VO_x或MoO_x形成混合氧化物：在这种情况下，一些二元金属氧化物形成均匀的固溶体；但有些二元氧化物不形成固溶体。若o_2或IrO_2的结晶受到其他金属元素的干扰，形成非晶状的高多孔氧化层。在某些情况下，添加的氧化物对贵金属氧化物颗粒或部分合金混合氧化物起支撑材料的作用。稀土元素形成raney型多孔氧化层：用钌氯化物和稀土的醇溶液浸涂法制备RuO_2（或IrO_2）-REO_x/Ti电极，浸涂法制备稀土（RE）元素。结果表明，RuO_2(30)-VO_x(70)/Ti电极赝电容最大，其次是RuO_2(50)-MoO_x(50)/Ti电极。raney型RuO_2和IrO_2电极的电容值均大于RuO_2- sno_2和RuO_2- tio_2电极，但小于RuO_2(30)-VO_x(70)/Ti和RuO_2(50)-MoO_x(50)/Ti电极。

The purpose of this research project is to design highly porous oxide-coated electrodes having large pseudo-capacitance which are capable to be loaded on electric vehicles. Following two methods have been applied to prepare RuO_2-or IrO_2-base electrodes with large pseudo-capacitance.1.Formation of mixed oxides with SnO_2, TiO_2, VO_x or MoO_x by dip-coating method : In this case, some binary metal oxides form homogeneous solid solution ; however, some binary oxides do not form solid solution. The crystallization of RuO_2 or IrO_2 is disturbed by the addition of other metal element, resulting in the formation of amorphous-like higly porous oxide layr. In some cases, the added oxide plays a role of supporting material for the noble metal oxide particles or partially alloyed mixed oxide.2.Formation of Raney-type porous oxide layr with rare earth element : These electrodes were prepared by leaching out of rare earth (RE) element from RuO_2 (or IrO_2)-REO_x/Ti electrodes, which were prepared by dip-coating method using alcoholic solutions of chlorides of ruthenium and a RE.It has been found that a dip-coated RuO_2(30)-VO_x(70)/Ti electrode gave the maximum value of the pseudo-capacitance followed by a RuO_2(50)-MoO_x(50)/Ti electrode. Although thecapacitance of the both Raney-type-RuO_2 and IrO_2 electrodes gave larger values than those of RuO_2-SnO_2 and RuO_2-TiO_2, it was samaller than those of RuO_2(30)-VO_x(70)/Ti and RuO_2(50)-MoO_x(50)/Ti electrodes.