本研究提出了一種基於N摻雜並活化的軟碳電極和使用Water-in-salt electrolyte（WISE）的對稱超級電容器。首先通過氫氧化鉀活化軟碳，以擴大表面積並增加活性位點，然後使用微波水熱法利用環六亞甲基四胺對軟碳進行氮摻雜，以引入其官能團，改善表面親水性及導電性。並利用醋酸鉀混合醋酸鈉當作電解液（Bi-salt WISE）以增加電位窗範圍。利用使用掃描電子顯微鏡（SEM）、表面積及奈米孔徑分析儀（BET）、拉曼散射光譜（RAMAN）和X射線光電子能譜（XPS）分析處理過軟碳的表面型態及元素，結果顯示成功將2.1 %的氮摻雜在軟碳中。將所製備的軟碳塗覆到碳布基板上當作電極，在對稱系統中進行了各種電化學評估，例如循環伏安法（CV）、恆電流充放電（GCD）和電化學阻抗譜（EIS）。本研究展示出色電化學性能，包括2.1 V的寬電位窗口、1050 F/g的優異比電容（在0.8 A/g）、在2138 W/kg的功率密度下，具有92.6 Wh/kg卓越的能量密度。

“Water-in-salt” has known as a novel electrolyte for widening the potential window in energy storage devices. In this work, we present an symmetric supercapacitor based on N-doped soft carbon electrode and the use of water-in-salt electrolyte. Soft carbon was first activated by potassium hydroxide to enlarge the surface area and increase active sites. Nitrogen was then doped to introduce additional functional groups using microwave-assisted hydrothermal treatment. The properties of the treated soft carbon were investigated using scanning electron microscope (SEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The as-prepared soft carbon was coated onto a carbon cloth substrate and used as electrode in symmetric supercapacitor. Various electrochemical evaluations, such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) were performed. We demonstrate the excellent electrochmeical performce of the symmetric supercapacitor, including a wide potential window of 2.1.

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