Hybrid Effect of Micropatterned Lithium Metal and Three Dimensionally Ordered Macroporous Polyimide Separator on the Cycle Performance of Lithium Metal Batteries

Abstract

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 LiNi 0.6 Mn 0.2 Co 0.2 O 2 /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.

Recent Progress of Porous Materials in Lithium‐Metal Batteries

“…Recently, intensive investigations on separator modification have been realized and applied in Li-metal protection. [51,[163][164][165][166][167][168][169][170][171][172][173][174][175][176] An advanced separator with high mechanical strength can prevent Li dendrites from penetrating it. In addition, the narrow pore size distribution and functionalities of modified separators can regulate homogenous Li-ion flux near the electrode surface and thus promote uniform Li nucleation and growth.…”

Polyimide separators for rechargeable batteries

“…The Kanamura group developed 3DOM PI separators using a colloidal crystal templating method [43,44,[109][110][111][112]. Fig.…”

Recent Advances on Materials for Lithium-Ion Batteries

“…Stability parameters, such as thermal and mechanical characteristics, are the easiest to achieve, as the properties of the separator components are well known and easily combined. Polyimide (PIs) is widely used in the separator field due to the improved thermal stability and different separators based on this polymer are being developed, such as PI nonwovens with diphenyl phosphate (DPhP) as plasticizer [204], PI with organic montmorillonite (OMMT) [205], a three-dimensionally ordered microporous polyimide (3DOM PI) separator developed by micropatterning [206], coating of silicon nitride on both sides of polyimide separator [207], and a PVDF-HFP/PI side-by-side bicomponent electrospun separator [208]. In addition to PI, other polymers such as poly(aryl ether benzimidazole) (OPBI) [209], polydopamine-coated poly(m-phenylene isophthalamid) membrane [210], and poly(phenylene sulfide) [211] are used due to their high thermal resistance.…”