Form Factor-Free, Printed Flexible Batteries

Sang-Young Lee
Ulsan National Institute of Science and Technology (UNIST)
Nov. 30 14:30~15:00


Forthcoming wearable/flexible electronics with compelling shape diversity and mobile usability have garnered significant attention as a kind of disruptive technology to drastically change our daily lives. From a power source point of view, conventional rechargeable batteries (represented by lithium-ion batteries) with fixed shapes and dimensions are generally fabricated by winding (or stacking) cell components (such as anodes, cathodes and separator membranes) and then packaging them with (cylindrical-/rectangular-shaped) metallic canisters or pouch films, finally followed by injection of liquid electrolytes. In particular, the use of liquid electrolytes gives rise to serious concerns in cell assembly, because they require strict packaging materials to avoid leakage problems and also separator membranes to prevent electrical contact between electrodes. For these reasons, the conventional cell assembly and materials have pushed the batteries to lack of variety in form factors, thus imposing formidable challenges on their integration into versatile-shaped electronic devices. Here, as an innovative strategy to address the aforementioned longstanding challenges, we demonstrate a new class of printed rechargeable power sources (including lithium-ion batteries and supercapacitors) with exceptional form factors and aesthetic versatility, which lie far beyond those achievable with conventional battery technologies. A key-enabling technology for this new battery system is to design battery inks (specifically, electrode and electrolyte inks), with a focus on their chemistry and rheology. Particular attention of this talk is devoted to discussing effects of the battery inks on printing processability, microstructure (focusing on bicontinuous ion/electron transport channels) and electrochemical performance of the printed batteries.

1)Han-Don Um, Keun-Ho Choi, Inchan Hwang, Se-Hee Kim, Kwanyong Seo, and Sang-Young Lee*, “Monolithically integrated, photo-rechargeable portable power sources based on miniaturized  Si solar cells and printed solid-state lithium-ion batteries”, Energy & Environ. Sci. 2017, 10, 931.
2)Keun-Ho Choi, JongTae Yoo, Chang Kee Lee and Sang-Young Lee* “All-inkjet-printed, solid-state flexible supercapacitors on paper” Energy & Environ. Sci. 2016, 9, 2812.
3)Se-Hee Kim, Keun-Ho Choi, Sung-Ju Cho, Sinho Choi, Soojin Park, and Sang-Young Lee* “Printed Solid-State Lithium-Ion Batteries: A New Route Toward Shape-Conformable Power Sources with Aesthetic Versatility for Flexible Electronics” Nano Letters 2015, 15, 5168.
4)Eun-Hye Kil, Keun-Ho Choi, Hyo-Jeong Ha, Sheng Xu, John A. Rogers, Mi Ri Kim, Young-Gi Lee, Kwang Man Kim, Kuk Young Cho*, Sang-Young Lee* “Imprintable, bendable, and shape-conformable polymer electrolytes for versatile-shaped lithium-ion batteries” Advanced Materials 2013, 25, 1395.



  • 2001.06-2002.12, Postdoctoral Research Associate,
    – Max Planck Institute for Polymer Research, Germany (Advisor: Prof. Gerhard Wegner)
  • 1993.03-1997.02, Ph.D. Dept. Chemical Engineering, KAIST, Korea (Advisor: Prof. Sung Chul Kim)
  • 1991.03-1993.02, M.S. Dept. of Chemical Engineering, KAIST, Korea
  • 1987.03-1991.02, B.S. Dept. of Chemical Technology, Seoul National Univ., Korea


Professional Career

  • 2016.01-, Head, School of Energy and Chemical Engineering, UNIST
  • 2015.09-, Professor, School of Energy and Chemical Engineering, UNIST
  • 2014.03-, Director of BK21 Plus Program, UNIST
  • 2014.03-2015.12, Dean of Student Affairs, UNIST
  • 2012.12-2015.09, Associate Professor, Dept. of Energy Engineering, UNIST
  • 2008.12-2012.12, Associate Professor, Dept. of Chemical Engineering, Kangwon National Univ.
  • 1997.01-2008.12, Principal Researcher, Batteries R&D, LG Chem.


Awards and Honors

  • 2015.05, (Korea) NRF Research Grant: “Challenge” ($900,000 for 3 years)
  • 2015.05, Editorial Board Member, Scientific Reports (Nature Publishing Group)
  • 2015.03, Best Teaching Award, UNIST
  • 2014.11, Top 50 Basic Research Awards, NRF
  • 2013.02, Excellence in Reviewing, J. Membr. Sci., Elsevier
  • 2012.12, Kangwon Top 10 Patent Awards
  • 2012.06, Main Coordinator of the 16th International Meeting on Lithium Batteries (IMLB)
  • 2007.05, NET Award, MEST
  • 2005.12, Grand Prize of the LG Chem Patent, LG Chem.
  • 1994-1996, Scholarship from LG Chem.
  • 1989-1990, Scholarship from Hanwha Group