Metal doping MnO₂ has better electrochemical performance than pure MnO₂. We have demonstrated a facile approach for synthesizing Mg-doped MnO₂@ carbon cloth via a typical hydrothermal reaction. The intercalation of Mg²⁺ rapidly increases the operating window to 1.2 V. Compared to other metal ions (Co²⁺, Fe³⁺, Bi²⁺, Al³⁺, Cr²⁺) doping, Mg²⁺ doping further increases the lattice defects of MnO₂, achieving more vacancies, and effectively improving the performance of MnO₂. As a flexible symmetric solid supercapacitor (FSSSC), the voltage window can be extended to 2.2 V, and the energy density of FSSSC reaches 2.06 mW h/cm³ at 43.94 mW/cm³. The device can illuminate a 2.2 V LED successfully, showing its huge actual application value.

金属掺杂MnO ₂具有比纯MnO ₂更好的电化学性能。我们已经证明了通过典型的水热反应合成掺Mg的MnO ₂ @碳布的简便方法。Mg ²⁺的插入将操作窗口迅速增加至1.2V。与其他金属离子（Co 2 ⁺，Fe ³⁺，Bi 2 ⁺，Al ³⁺，Cr ²⁺）掺杂相比，Mg ²⁺掺杂会进一步增加MnO _2的晶格缺陷，实现更多的空位，有效提高MnO ₂的性能。作为柔性对称固体超级电容器（FSSSC），电压窗口可以扩展到2.2 V，和FSSSC的能量密度达到2.06毫瓦H /厘米³，在43.94毫瓦/厘米³。该设备可以成功点亮2.2 V LED，显示出其巨大的实际应用价值。