Herein, lignin-rich KOH-activated porous carbon from eucalyptus wood (named as PACE) is presented as an efficient electrode for supercapacitors (SCs). Compared with the most commonly used higher activation temperature, i.e., 800 °C with KOH (PACE-800), a more efficient SC is developed by activating carbon with KOH at lesser temperature, i.e., 600 °C (PACE-600). The high specific capacitance (i.e., 230 F g⁻¹ at 1 A g⁻¹ measured in a 2 m NaCl electrolyte) measured by galvanostatic charge–discharge (GCD) studies is not primarily due to larger surface area, but due to the inherent electron-rich oxygen-based functionalities that persist at the lower activation temperature, contributing to the hydrophilic nature to PACE-600. The mechanism of the capacitive charge storage is deduced from electrochemical impedance spectroscopy (EIS). The application of PACE-600 as a SC electrode is confirmed from insignificant loss in the specific capacitance after 10 000 charging–discharging cycles, recorded at 10 A g⁻¹. Further, fabrication of higher-voltage (1.6 V) symmetric SC PACE-600//PACE-600 in aqueous neutral electrolyte (2 m NaCl) is presented, which illuminates a red LED (1.8 V) for 1 min after charging for 5 s. The corresponding energy density is calculated to be 41 W h kg⁻¹, and at a power density of 2396 W kg⁻¹.

中文翻译：

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来自桉木的富氧多孔活性炭作为高效的超级电容器电极

在此，来自桉木的富含木质素的 KOH 活性多孔碳（命名为 PACE）被用作超级电容器（SC）的有效电极。与最常用的较高活化温度，即 800 °C 和 KOH (PACE-800) 相比，通过在较低温度，即 600 °C (PACE-600) 下用 KOH 活化碳，开发了更有效的 SC。高比电容（即 230 F g ^-1 at 1 A g ^-1在 2  m通过恒电流充放电 (GCD) 研究测量的 NaCl 电解质）主要不是由于更大的表面积，而是由于固有的富电子氧基官能团在较低的活化温度下持续存在，这有助于 PACE- 600。电容电荷存储的机制是从电化学阻抗谱（EIS）推导出来的。PACE-600 作为 SC 电极的应用证实了在 10 000 次充放电循环后比电容的显着损失，记录在 10 A g ^-1。此外，在水性中性电解质（2  mNaCl)，它在充电 5 秒后点亮红色 LED (1.8 V) 1 分钟。相应的能量密度计算为 41 W h kg ^-1，功率密度为 2396 W kg ^-1。