Scalable Preparation of Polyimide Sandwiched Separator for Durable High‐Rate Lithium‐Metal Battery

Abstract

The ever‐growing demands for efficient energy storage accelerate the development of high‐rate lithium‐metal battery (LMB) with desirable energy density, power density, and cycling stability. Nevertheless, the practical application of LMB is critically impeded by internal temperature rise and lithium dendrite growth, especially at high charge/discharge rates. It is highly desired but remains challenging to develop high‐performance thermotolerant separators that can provide favorable channels to enable fast Li+ transport for high‐rate operation and simultaneously homogenize the lithium deposition for dendrite inhibition. Polyimide‐based separators with superior thermal properties are promising candidate alternatives to the commercial polyolefin‐based separators, but previous strategies of designing either nanoporous or microporous channels in polyimide‐based separators often meet a dilemma. Here, a facile and scalable approach is reported to develop a polyimide fiber/aerogel (denoted as PIFA) separator with the microporous polyimide fiber membrane sandwiched between two nanoporous polyimide aerogel layers, which can enable LMBs with remarkable capacity retention of 97.2% after 1500 cycles at 10 C. The experimental and theoretical studies unravel that the sandwiched structure of PIFA can appreciably enhance the electrolyte adsorption and ionic conductivity; while, the aerogel coating can effectively inhibit dendrite growth to realize durable high‐rate LMBs.

Surface charge modulation boosts electrocatalytic water splitting over iridium catalysts on a polyimide support

“…25,26 In addition, the peaks at 1382 cm −1 are in accordance with the C–N stretching vibration in the imide ring of the PI material. 27,28 The X-ray diffraction (XRD) patterns of the synthesized Ir NP@PI and Ir NP catalysts are consistent with that of Ir metal (PDF # 46-1044).…”

Superspreading‐Based Fabrication of Thermostable Nanoporous Polyimide Membranes for High Safety Separators of Lithium‐Ion Batteries

“…[22] However, the low surface energy of the polyolefin separators and the difference in Young's modulus between both make the easy detachment of the inorganic coatings on its surface become another problem. [23,24] In contrast, thermostable polymeric materials, such as polyimide (PI), [25][26][27][28] cellulose, [29,30] polyacrylonitrile, [31] poly(etherether-ketone), [32] and aramid nanofibers [33][34][35] have been widely used to fabricate thermostable separators by using their excellent intrinsic properties, such as high thermal stability, high chemical stability, and easy manufacturing.…”