Hybrid Effect of Micropatterned Lithium Metal and
Three Dimensionally Ordered Macroporous Polyimide Separator on the
Cycle Performance of Lithium Metal Batteries
posted on 2020-03-19, 14:08authored byDohwan Kim, Hirokazu Munakata, Joonam Park, Youngjoon Roh, Dahee Jin, Myung-Hyun Ryou, Kiyoshi Kanamura, Yong Min Lee
Short
cycle life of the lithium metal secondary battery (LMSB)
is largely ascribed to the dendritic growth of lithium metal during
the charging process followed by continuous electrolyte decomposition.
To make up for this intrinsic drawback of lithium metal, two pioneering
techniques, micropatterning on lithium metal and three dimensionally
ordered microporous polyimide (3DOM PI) separator, are combined to
ascertain their hybrid effect on the cycle performance of LMSB. When
a unit cell consisting of LiNi0.6Mn0.2Co0.2O2/3DOM PI separator/patterned lithium metal
is cycled at the charging and discharging c-rates of 0.3C and 1C (1C
= 2.5 mA), respectively, above 80% of the initial discharge capacity
is maintained even after 400 cycles, while a control cell with polyethylene
separator survives only for 130 cycles. This tremendous improvement
is ascribed to the combination effect of inducing preferential lithium
electrodeposition reaction into the micropattern and the uniform distribution
of lithium ions on the nonpatterned lithium surface region by the
3DOM PI separator. Thus, combining these two technologies is very
promising for LMSB commercialization in the future.