신소재공학과

Seminar

Date 20161115 

■ Topic : Understanding the electrochemical storage mechanism in supercapacitors
                   
■ Speaker : 11/14(Tue) Prof. Sangeun Chun (Dept. of MSE, Kyungpook National Univ.)

 

■ Invitation : Prof. Yoon Sung Nam


■ Date & Time : November 15 (Tue) 16:00


■ Venue : KAIST Applied Engineering B/D(W1), Multimedia Lecture Hall (1st Floor)


■ Abstract : Electrochemical double-layer capacitors exhibit high power and long cycle life but have low specific energy compared with batteries, limiting applications. Redox-enhanced capacitors increase specific energy by using redox-active electrolytes that are oxidized at the positive electrode and reduced at the negative electrode during charging. Here we report characteristics of several redox electrolytes to illustrate operational/self-discharge mechanisms and the design rules for high performance. We discover a methyl viologen (MV)/bromide electrolyte that delivers a high specific energy of ~14 Wh kg-1 based on the mass of electrodes and electrolyte, without the use of an ion-selective membrane separator. Substituting heptyl viologen for MV increases stability, with no degradation over 20,000 cycles. Self-discharge is low, due to adsorption of the redox couples in the charged state to the activated carbon, and comparable to cells with inert electrolyte. An electrochemical model reproduces experiments and predicts that 3050 Wh kg-1 is possible with optimization.

No. Subject Author Date Views
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202 12/6 (Tue) Prof. KwangSup Eom (School of MSE, GIST) ADMINI 2016.12.02 923
201 [Special Seminar] 11/16(Wed), Dr. Seung-Kyun Kang (Dept. of MSE, University of Illinois at Urbana-Champaign) ADMINI 2016.11.16 926
» 11/14(Tue) Prof. Sangeun Chun (Dept. of MSE, Kyungpook National Univ.) ADMINI 2016.11.14 914
199 11/8(Tue) Dr. Nikolai Tsvetkov (EEWS, KAIST) ADMINI 2016.11.07 804
198 11/1(Tue) Prof. Seung Hwan Ko (Dept. of ME, Seoul National Univ.) ADMINI 2016.11.01 845
197 [Special Seminar] 10/19(Wed), Prof. Wei-Chuan Shih (Departments of Electrical & Computer Engineering, University of Houston) ADMINI 2016.10.18 776
196 10/18(Tue) Prof. Megumi Kawasaki (Dept. of MSE, Hanyang Univ.) ADMINI 2016.10.17 802
195 [Special Seminar] 10/11(Tue), Prof. Leon Abelmann (KIST Europe) ADMINI 2016.10.07 802
194 10/4(Tue) Prof. Junsuk Rho (Dept. of ME/CE, POSTECH) ADMINI 2016.10.04 941
193 10/4(Tue) KAIST Self-Assembly Symposium 2016 file ADMINI 2016.09.30 886
192 [Special Seminar] 9/30(Fri) Mark Ediger (University of Wisconsin-Madison / Department of Chemistry) ADMINI 2016.09.30 802
191 9/27(Tue) Prof. Sungtae Shin (Dept. of DSP, Korea Univ. Sejong Campus) ADMINI 2016.09.23 1331
190 9/20(Tue) Dr. Sang Soo Han, (KIST) ADMINI 2016.09.19 1367
189 9/6(Tue) Prof. Seung Yong Park, (The Nelson Mandela African Institution of Science and Technology, Head of the Department of Materials and Energy Science and Engineering) ADMINI 2016.08.29 1828
188 [Special Seminar] 8/23(Tue) Prof. Ji Hwan Kim (MIT) ADMINI 2016.08.22 1452
187 8/2(Tue) KAIST International MSE Workshop 2016 ADMINI 2016.07.25 2308
186 [Special Seminar] 6/15(Wed) Prof. Chanho Pak (GIST) ADMINI 2016.06.10 1459
185 6/14(Tue) Prof. Haein Yim, (Department of Physics, Sookmyung Women's Univ.) ADMINI 2016.06.09 1509
184 6/7(Tue) Dr. Soongu Kwon, (Center for Nanoparticle Research, Seoul National Univ.& Institute for Basic Science) ADMINI 2016.06.02 1407
183 5/31(Tue) Prof. Dongmok Whang, (School of AMSE, Sungkyunkwan Univ.) ADMINI 2016.05.27 1246