High temperature performances of yttrium-doped spherical nickel hydroxide
High temperature performances of yttrium-doped spherical nickel hydroxide
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DOI：
10.1016/j.electacta.2004.03.005
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发表时间：
2004-08
影响因子：
6.6
通讯作者：
X. Mi;X. P. Gao;Changyin Jiang;M. Geng;Jie Yan;C. Wan
中科院分区：
文献类型：
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作者：
X. Mi;X. P. Gao;Changyin Jiang;M. Geng;Jie Yan;C. Wan
采用化学共沉淀法合成了规则球形β相氢氧化镍和钇掺杂球形β相氢氧化镍。 TEM观察到长针状纳米晶的钇掺杂促进了较大直径约5μm的球形氢氧化镍的形成。在室温下测得掺钇球形氢氧化镍的放电容量略低于常规球形氢氧化镍的放电容量。然而，在50℃以上的温度下，掺钇氢氧化镍的放电容量远高于普通球形氢氧化镍。高温下放电容量的提高有助于提高钇掺杂氢氧化镍的充电接受能力。氢氧化镍颗粒上富钇表面层的形成提高了析氧过电位，从而提高了氢氧化镍电极的性能。掺钇氢氧化镍的高温充电接受能力的提高显着提高了商用 AAA 尺寸镍氢（Ni-MH）电池的高温充放电效率。
The regular and yttrium-doped spherical β-phase nickel hydroxides were synthesized by means of chemically co-precipitation. The yttrium-doping with long needle-like nanocrystallites observed by TEM promoted the formation of the spherical nickel hydroxide with the larger diameter of about 5μm. The discharge capacity of the yttrium-doped spherical nickel hydroxide was measured to be slightly lower than that of the regular spherical nickel hydroxide at room temperature. At temperatures of above 50°C, however, the discharge capacity of the yttrium-doped nickel hydroxide is much higher than that of the regular spherical nickel hydroxide. The improvement of discharge capacity at elevated temperatures was contributed to the increase of the charge acceptance of yttrium-doped nickel hydroxide. The formation of an yttrium-rich surface layer on nickel hydroxide particles raised the oxygen evolution over-potential, leading to performance improvements of the nickel hydroxide electrode. The improvement of high temperature charge acceptance of yttrium-doped nickel hydroxide remarkably contributed to the high temperature charge–discharge efficiency of the nickel–metal hydride (Ni–MH) batteries with a commercial AAA size.