New Physics: Sae Mulli, Vol. 69, No. 2, February 2019, pp. 159∼164 http://dx.doi.org/10.3938/NPSM.69.159 Comparative Study of WO 3 Performance as Supercapacitor Electrodes Synthesized Using Diferent Acids Chihoon Kim · Vaibhav Lokhande · Soojeong Go · Taeksoo Ji * Department of Electronics and Computer Engineering, Chonnam National University, Gwangju 61186, Korea (Received 8 November 2018 : revised 4 December 2018 : accepted 17 December 2018) In this study, the synthesis of WO 3 using diferent acids was carried out to test its electrochemical performance and applicability in electrochemical charge storage devices like supercapacitors. Hy- drochloric acid (W1), sulfuric acid (W2) and nitric acid (W3) were used to synthesize WO 3 , which was deposited on a carbon cloth substrate via a hydrothermal route. X-ray difraction (XRD) characterization confrmed the formation of hexagonal WO3 in all three samples. Scanning elec- tron microscopy (SEM) was performed to analyze the morphology, size and shape of the deposited material, and diferent nano structures, such as nano spheres, nano rods and hexagonal platelets, were observed, which confrms the efect of diferent acids on the morphology, shape and size of the particle. Electrochemical characterizations using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests suggest that the samples exhibit charge-storage capability and can be utilized as active materials in energy storage devices. Sample W2 exhibits highest specifc ca- pacitance of 778 Fg -1 at 5 mVs -1 scan rate while W1 showed the lowest specifc capacitance (500 Fg -1 at 5 mVs -1 ) of all three samples. The efect of acid on WO3 parameters and consequently its electrochemical performance has been discussed further. PACS numbers: 88.80.-q, 82.30.-b, 82,45.-h Keywords: Supercapacitor, Energy storage, Hydrothermal reaction 수열 합성으로 제조된 WO 3 의 산용액에 따 슈퍼축전기 전극 특성 연구 김치훈 · Lokhande Vaibhav · 고수정 · 지택수 * 전남대학교 전자컴퓨터공학부, 광주 61186, 대한민국 (2018 년 11 월 8 일 받음, 2018 년 12 월 4 일 수정본 받음, 2018 년 12 월 17 일 게재 확정) 본 연구에서는 세 가지의 상이한 산성용액을 변수로 제조된 WO 3 의 특성을 분석하였다. 산성 용액은 수열합성 공정 시 첨가되는 변수로서 염산 (W1), 황산 (W2), 질산 (W3) 을 각각 이용하였고, 제조된 샘플을 바탕으로 주사전자현미경 (SEM), X-선 회절분석기 (X-ray difraction, XRD) 와 전기화학적 특성 테스트를 실시하였다. 염산용액과 질산용액에서 제조된 샘플에서는 6 각형의 혈소판 결정과 나노 구체 모양을 확인할 수 있고, 황산용액에서 제조된 샘플에서는 나노구체와 나노큐브 모양을 확인 할 수 있다. 또한 XRD 데이터는 모두 회절 피크가 육방정 결정 (hexagonal phase) 을 가지는 것으로 확인 되었다. 전기 화학적인 특성을 분석한 결과 W2 샘플의 정전용량이 가장 높지만 (778 Fg -1 at 5 mVs -1 ) 방전용량비 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.