Atomic Layer Deposition (ALD) of Alumina over Activated Carbon Electrodes Enabling a Stable 4 V Supercapacitor Operation

TY - JOUR

T1 - Atomic Layer Deposition (ALD) of Alumina over Activated Carbon Electrodes Enabling a Stable 4 V Supercapacitor Operation

AU - Gandla, Dayakar

AU - Song, Guanghui

AU - Wu, Chongrui

AU - Ein-Eli, Yair

AU - Tan, Daniel Q.

N1 - Publisher Copyright: © 2021 The Authors. Published by Wiley-VCH GmbH Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/4

Y1 - 2021/4

N2 - Designing high voltage (>3 V) and stable electrochemical supercapacitors with low self-discharge is desirable for the applications in modern electronic devices. This work demonstrates a 4 V symmetric supercapacitor with stabilized cycling performance through atomic layer deposition (ALD) of alumina (Al2O3) on the surface of activated carbon (AC). The 20-cycle ALD Al2O3 coated AC delivers 84 % capacitance retention after 1000 charge/discharge cycles under 4 V, contrary to the bare AC cells having only 48 % retention. The extended cycling life is associated with the thickened Stern layer and suppressed oxygen functional group. The self-discharge data also show that the Al2O3 coating enables AC cells to maintain 53 % of charge retention after 12 h, which is more than twice higher than that of bare AC cells under the same test protocol of 4 V charging. The curve fitting analysis reveals that ALD coating induced slow self-discharge dominated by ion diffusion mechanism, thus enhancing the AC surface energy.

AB - Designing high voltage (>3 V) and stable electrochemical supercapacitors with low self-discharge is desirable for the applications in modern electronic devices. This work demonstrates a 4 V symmetric supercapacitor with stabilized cycling performance through atomic layer deposition (ALD) of alumina (Al2O3) on the surface of activated carbon (AC). The 20-cycle ALD Al2O3 coated AC delivers 84 % capacitance retention after 1000 charge/discharge cycles under 4 V, contrary to the bare AC cells having only 48 % retention. The extended cycling life is associated with the thickened Stern layer and suppressed oxygen functional group. The self-discharge data also show that the Al2O3 coating enables AC cells to maintain 53 % of charge retention after 12 h, which is more than twice higher than that of bare AC cells under the same test protocol of 4 V charging. The curve fitting analysis reveals that ALD coating induced slow self-discharge dominated by ion diffusion mechanism, thus enhancing the AC surface energy.

KW - activated carbon

KW - atomic layer deposition

KW - high voltage

KW - self-discharge

KW - supercapacitors

UR - http://www.scopus.com/inward/record.url?scp=85100895771&partnerID=8YFLogxK

U2 - 10.1002/open.202000352

DO - 10.1002/open.202000352

M3 - 文章

C2 - 33590713

AN - SCOPUS:85100895771

SN - 2191-1363

VL - 10

SP - 402

EP - 407

JO - ChemistryOpen

JF - ChemistryOpen

IS - 4

ER -