A facile chemical precipitation method is used to prepare both lanthanum hydroxide [La(OH)₃] and neodymium hydroxide [Nd(OH)₃] nanopowders in an ambient temperature without the addition of any surfactants. Both rare‐earth hydroxides nanopowders are characterized by X‐ray diffraction and FE‐SEM analysis. The supercapacitor performances of La(OH)₃ and Nd(OH)₃ electrodes are studied by cyclic voltammetry, electrochemical AC‐impedance and galvanostatic charge‐discharge studies. It revealed that Nd(OH)₃ electrode possesses a high specific capacitance (C_sp) than La(OH)₃ electrode. Hence, an asymmetric supercapacitor device is fabricated and denoted as Nd(OH)₃||AC in 6 M KOH as the electrolyte soaked in the electrospun poly(vinylidene fluoride) membrane as the separator, which exhibited an energy density of 18.8 Wh kg⁻¹ at a power density of 796 W kg⁻¹.

中文翻译：

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Nd（OH）3和La（OH）3纳米粉体合成的简易化学沉淀方法及其超级电容器性能

在环境温度下，不添加任何表面活性剂的情况下，使用简便的化学沉淀法来制备氢氧化镧[La（OH）₃ ]和氢氧化钕[Nd（OH）₃ ]纳米粉。两种稀土氢氧化物纳米粉均通过X射线衍射和FE-SEM分析表征。通过循环伏安法，电化学交流阻抗和恒电流充放电研究了La（OH）₃和Nd（OH）₃电极的超级电容器性能。结果表明，Nd（OH）₃电极比La（OH）₃具有更高的比电容（C _sp）电极。因此，非对称超级电容器装置被制造并且表示为钕（OH）₃ || AC在6M KOH作为电解质中的电纺丝的聚（偏氟乙烯）膜作为隔离物，其显示的18.8瓦kg的能量密度浸泡^{- 1}在796公斤w ^的功率密度^-1。