A high-performance supercapacitor based on an amorphous MnO₂ electrode on Ni foam (MnO₂/NF) in a Na₂SO₄/KOH mixed electrolyte was fabricated and studied. XRD, Raman, TEM, and SEM characterizations highlighted the nanostructure of these amorphous MnO₂ materials. The electrochemical behaviors of amorphous MnO₂/NF were studied using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) measurements, and the cycling performance. The results reveal that the amorphous MnO₂/NF in the Na₂SO₄/KOH electrolyte exhibited a high capacitance. The Na₂SO₄/KOH mixed electrolyte with ionic interactions in the mesopores increased the capacitance. However, weaker ion-interacting cations can diffuse into microspores without losing their capacitive ability. An asymmetric supercapacitor has been developed successfully with amorphous MnO₂ and graphene nanosheets (GNs)/multiwalled carbon nanotubes (MWCNTs) as the positive and negative electrodes, respectively. The MnO₂//GNS–MWCNT (GM) asymmetric supercapacitor exhibits a maximum energy density of 43.3 Wh kg⁻¹ at a power density of 500 W kg⁻¹.

在Na ₂ SO ₄ / KOH混合电解质中，基于Ni泡沫（MnO ₂ / NF）上的非晶MnO ₂电极，制造并研究了一种高性能超级电容器。XRD，拉曼，TEM和SEM表征突出了这些非晶态MnO ₂材料的纳米结构。使用循环伏安法（CV），恒电流充放电（GCD）测量和循环性能研究了非晶态MnO ₂ / NF的电化学行为。结果表明，Na ₂ SO ₄ / KOH电解质中的非晶态MnO ₂ / NF表现出高电容。Na ₂ SO ₄在中孔中具有离子相互作用的/ KOH混合电解质增加了电容。但是，较弱的离子相互作用阳离子可以扩散到微孢子中，而不会失去其电容能力。已成功开发出了以非晶态MnO ₂和石墨烯纳米片（GNs）/多壁碳纳米管（MWCNTs）作为正电极和负电极的不对称超级电容器。MnO的₂ // GNS-MWCNT（GM）的不对称超级电容器表现出43.3瓦公斤的最大能量密度^-1在500瓦kg的功率密度^-1。