木质素基碳纳米片组装木陶瓷电极的结构调控与电化学储能

Structural Regulation and Electrochemical Energy Storage of Woodceramic Electrode Assembled with Lignin Based Carbon Nanosheet

以杨木基木陶瓷为骨架,采用电沉积法组装黑液木质素,经高温烧结和物理活化制备木质素基碳纳米片组装块状木陶瓷电极,并对序列组装机制、结构与形貌、物相构成、电化学储能机制和电化学性能进行了探讨与分析。结果表明:黑液木质素在电场的作用下可按照一定的序列组装在木陶瓷骨架的表面与孔隙中,高温烧结后木质素转化为碳纳米片,部分依然保持有序排列;同时,所制备的木陶瓷电极主要由无定型炭与石墨微晶构成,具有多层次孔隙,且木质素的组装可优化孔隙结构。其中电沉积10 min、1000℃保温烧结2 h、180℃活化6 h的试件具有较好的电化学性能:在扫描速率为0.25 A·g-1时比电容可达141.8 F·g-1;充放电循环1000次后比电容保持率为88.1%;在能量密度为132.6 Wh·kg-1时,功率密度达12.8 W·kg-1,该木陶瓷电极具有较好的储能性能与应用潜力。

Blocky woodceramic electrode was prepared by high temperature sintering and physical activation which uses poplar based woodceramics as skeleton and assembled pulping black liquor lignin based carbon nanosheet with electrodeposition method.The electrochemical deposition mechanism,structure and morphology,phase composition,chemical energy storage mechanism and electrochemical performance had been discussed and analyzed.The results showed that pulping black liquor lignin was assembled on the surface and in the pores of woodceramics skeleton in a certain sequence under the action of electric field,and the lignin was converted into carbon nanometer sheets after high temperature sintered,some of them still remained the orderly arrangement.Meanwhile,the electrode was mainly composed of amorphous carbon and graphite microcrystalline with multilayer pores,which could be regulated and optimized by the assembly of lignin.The specimen had better electrochemical performance,which electrodeposited for 10 min,sintered at 1000℃for 2 h and activated at 180℃for 6 h.When the scanning rate was 0.25 A·g-1,the specific capacitance could reach 141.8 F·g-1,and the specific capacitance retention rate was 88.1%after 1000 cycles of charge and discharge.As the energy density was 132.6 Wh·kg-1,the power density was 12.8 W·kg-1,indicating a good energy storage perfor-mance and application potential.