Boosting Pseudocapacitive Behavior of Supercapattery Electrodes by Incorporating a Schottky Junction for Ultrahigh Energy Density  

作　　者：Selvaraj Seenivasan Kyu In Shim Chaesung Lim Thangavel Kavinkumar Amarnath T.Sivagurunathan Jeong Woo Han Do-Heyoung Kim 

机构地区：[1]School of Chemical Engineering,Chonnam National University,77 Yongbong-Ro,Gwangju 61186,Republic of Korea [2]Division of Environmental Science and Engineering,Pohang University of Science and Technology(POSTECH),Pohang 37673,Republic of Korea [3]Department of Chemical Engineering,Pohang University of Science and Technology(POSTECH),Pohang 37673,Republic of Korea

出　　处：《Nano-Micro Letters》2023年第5期15-35,共21页纳微快报（英文版）

基　　金：financially supported by the National Research Foundation of Korea(NRF-2022R1A2C2010803)。

摘　　要：Pseudo-capacitive negative electrodes remain a major bottleneck in the development of supercapacitor devices with high energy density because the electric double-layer capacitance of the negative electrodes does not match the pseudocapacitance of the corresponding positive electrodes.In the present study,a strategically improved Ni-Co-Mo sulfide is demonstrated to be a promising candidate for high energy density supercapattery devices due to its sustained pseudocapacitive charge storage mechanism.The pseudocapacitive behavior is enhanced when operating under a high current through the addition of a classical Schottky junction next to the electrode-electrolyte interface using atomic layer deposition.The Schottky junction accelerates and decelerates the diffusion of OH-/K+ions during the charging and discharging processes,respectively,to improve the pseudocapacitive behavior.The resulting pseudocapacitive negative electrodes exhibits a specific capacity of 2,114 C g^(-1)at 2 A g^(-1)matches almost that of the positive electrode’s 2,795 C g^(-1)at 3 A g^(-1).As a result,with the equivalent contribution from the positive and negative electrodes,an energy density of 236.1 Wh kg^(-1)is achieved at a power density of 921.9 W kg^(-1)with a total active mass of 15 mg cm-2.This strategy demonstrates the possibility of producing supercapacitors that adapt well to the supercapattery zone of a Ragone plot and that are equal to batteries in terms of energy density,thus,offering a route for further advances in electrochemical energy storage and conversion processes.

关 键 词：PSEUDO-CAPACITANCE Negative electrode Supercapattery Atomic layer deposition Energy density 

分 类 号：O646.54[理学—物理化学] TM53[理学—化学]