Preparation of manganese oxides with nanosize structu re for energy storage devices by electrochemical precipitation technic.

用电化学沉淀法研究了Mn（OH）2的电化学行为。在快扫描速率下，Mn（II）/Mn（III）体系在KOH水溶液中发生可逆氧化还原反应。同时伴有OH-的插入和脱附，但无碱金属离子。在慢扫描速率下，证实了在电化学氧化过程中碱金属离子电化学插入到电化学沉淀的Mn（OH）_2中。以Mn（NO_3）_2和Al（NO_3）_3为原料，采用恒电流电化学还原法在Pt基底上制备了层间距为0.88 nm的层状锰铝双氢氧化物（Mn/Al LDH）。在2 mol dm^ KOH溶液中，首次电化学氧化时，Al^3+在LDH中发生溶解<-3>，但在2次循环后，在-0.2Vvs. Hg/HgO附近观察到可逆的氧化还原峰<nd>。

Electrochemical behavior of Mn(OH)_2 was successfully investigated using the electrochemically precipitated Mn(OH)_2.At the fast scan rate, reversible redox reaction proceeds among Mn(II)/Mn(III) system in KOH aq. accompanied with insertion and desorption of OH-but no alkali metal ions. At the slow scan rate, electrochemical insertion of alkali metal ions into electrochemically precipitated Mn(OH)_2 was confirmed during electrochemical oxidation. Layered Manganese and aluminum double hydroxides(Mn/Al LDH), the interlayer spacing of 0.88 nm, were electrochemically synthesized on a Pt substrate by galvanostatic electrochemical reduction of Mn(NO_3)_2 and Al(NO_3)_3 aqueous solutions mixtures. Though the dissolution of Al^<3+> in the LDHs occurred at the first electrochemical oxidation in a 2 mol dm^<-3> KOH solution, reversible redox peaks at around-0.2V vs. Hg/HgO were observed after 2^<nd> cycle of CVs.