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
Notice 11/28 (Tue) Dr. Woo-Jin Lee (Ministry of Science and ICT.) ADMINI 2017.11.24 5
Notice 2017 The Fall Semester Seminar ADMINI 2017.09.08 1455
206 02/20 (Mon) Special Seminar Announcement, Prof. Hwang (Seoul National University) ADMINI 2017.02.14 1190
205 02/08 (Wed) Special Seminar Announcement, Dr. Yong Ho Kang, UC Santa Barbara ADMINI 2017.02.02 1480
204 [Special Seminar] 12/23(Wed), Dr. Jaejin Kim (Chemical Sciences and Engineering Division, Argonne National Laboratory) ADMINI 2016.12.16 1355
203 12/13(Tue) Dr. Jae Yong Song (KRISS) ADMINI 2016.12.12 1383
202 12/6 (Tue) Prof. KwangSup Eom (School of MSE, GIST) ADMINI 2016.12.02 1187
201 [Special Seminar] 11/16(Wed), Dr. Seung-Kyun Kang (Dept. of MSE, University of Illinois at Urbana-Champaign) ADMINI 2016.11.16 1224
» 11/14(Tue) Prof. Sangeun Chun (Dept. of MSE, Kyungpook National Univ.) ADMINI 2016.11.14 1187
199 11/8(Tue) Dr. Nikolai Tsvetkov (EEWS, KAIST) ADMINI 2016.11.07 1155
198 11/1(Tue) Prof. Seung Hwan Ko (Dept. of ME, Seoul National Univ.) ADMINI 2016.11.01 1107
197 [Special Seminar] 10/19(Wed), Prof. Wei-Chuan Shih (Departments of Electrical & Computer Engineering, University of Houston) ADMINI 2016.10.18 1079
196 10/18(Tue) Prof. Megumi Kawasaki (Dept. of MSE, Hanyang Univ.) ADMINI 2016.10.17 1086
195 [Special Seminar] 10/11(Tue), Prof. Leon Abelmann (KIST Europe) ADMINI 2016.10.07 1066
194 10/4(Tue) Prof. Junsuk Rho (Dept. of ME/CE, POSTECH) ADMINI 2016.10.04 1204
193 10/4(Tue) KAIST Self-Assembly Symposium 2016 file ADMINI 2016.09.30 1194
192 [Special Seminar] 9/30(Fri) Mark Ediger (University of Wisconsin-Madison / Department of Chemistry) ADMINI 2016.09.30 1096
191 9/27(Tue) Prof. Sungtae Shin (Dept. of DSP, Korea Univ. Sejong Campus) ADMINI 2016.09.23 1610
190 9/20(Tue) Dr. Sang Soo Han, (KIST) ADMINI 2016.09.19 1629
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 2159
188 [Special Seminar] 8/23(Tue) Prof. Ji Hwan Kim (MIT) ADMINI 2016.08.22 1729
187 8/2(Tue) KAIST International MSE Workshop 2016 ADMINI 2016.07.25 2652