Youngjoon Roh1, Seoungwoo Byun1, Myung-Hyun Ryou2,**, and Yong Min Lee1,*노영준1·변승우1·유명현2,**·이용민1,*
1Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST)
2Department of Chemical and Biological Engineering, Hanbat National University1대구경북과학기술원 에너지공학전공, 2한밭대학교 화학생명공학과
To maximize the areal capacity(mAh cm-2) of LiNi0.5Co0.2Mn0.3O2(NCM523) electrode
with the same loading level of 15 mg cm-2, three NCM523 electrodes with 4, 2, and 1 wt%
poly(vinylidene fluoride)(PVdF) binder content are fabricated. Due to the delamination issue of
electrode composite at the edge during punching process, the 1 wt% electrode is excluded for further
evaluation. When the PVdF binder content decreases from 4 to 2 wt%, both adhesion strength
and shear stress decrease from 0.4846 to 0.2627 kN m-1 by -46% and from 3.847 to 2.013 MPa
by -48%, respectively. Regardless of these substantial decline of mechanical properties, their initial
electrochemical properties such as initial coulombic efficiency and voltage profile are almost the
same. However, owing to high loading level, the 2 wt% electrode not only exhibits worse cycle
performance than the 4 wt% electrode, but also cannot maintain its mechanical integrity only after
80 cycles. Therefore, if the binder content is reduced to increase the area capacity, the mechanical
properties as well as the cycle performance must be carefully evaluated.
Keyword : Electrode binder, Electrochemical property, Adhesion strength, SAICAS, Lithium
secondary battery