Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian 116034, China.
Int J Biol Macromol. 2021 Jan 1;166:923-933. doi: 10.1016/j.ijbiomac.2020.10.249. Epub 2020 Nov 2.
Three-dimensional hierarchical porous carbon is prepared by utilizing enzymatic hydrolysis lignin as a carbon source via hydrothermal carbonization and activation. The complicated operational parameters including temperature, time, concentration and pH in the hydrothermal carbonization are systemically investigated. We employed the hydrochar as electrode for supercapacitors. Accordingly, we not only achieve a high-performance specific capacitance for supercapacitors but also rationalize the effects of hydrothermal conditions on the specific capacitance via various characterizations. The activation process of hydrochar is also studied by comparing various activators and the activator/hydrochar ratios. The obtained materials possess a three-dimensional interconnected hierarchical structure with rational pore size distribution and a specific surface area reach up to 1504 m g. Then the corresponding supercapacitors achieve a large specific capacitance of 324 F g as the current density is 0.5 A g. These supercapacitors acquire an outstanding cycling stability with 99.7% capacitance retention after 5000 cycles. The assembled symmetrical supercapacitors also show a high energy density of 17.9 W h kg and can maintain at 5.6 W h kg even at an ultra-high power density of 50,400 W kg.
采用酶解木质素作为碳源，通过水热碳化和活化制备三维分级多孔碳。系统研究了水热碳化中复杂的操作参数，包括温度、时间、浓度和 pH 值。我们将水热碳化得到的碳用作超级电容器的电极。因此，我们不仅实现了超级电容器的高比电容，还通过各种表征方法合理地解释了水热条件对比电容的影响。通过比较不同的活化剂和活化剂/水热碳的比例，研究了水热碳的活化过程。所得到的材料具有三维互连的分级结构，具有合理的孔径分布和比表面积可达 1504 m²/g。相应的超级电容器在电流密度为 0.5 A/g 时具有 324 F/g 的大比电容。这些超级电容器具有出色的循环稳定性，经过 5000 次循环后，电容保持率为 99.7%。组装的对称超级电容器也表现出高能量密度为 17.9 Wh/kg，即使在超高功率密度 50400 W/kg 下，仍能保持在 5.6 Wh/kg。
