Porous membrane with high curvature, three-dimensional heat-resistance skeleton: a new and practical separator candidate for high safety lithium ion battery

Abstract

Separators with high reliability and security are in urgent demand for the advancement of high performance lithium ion batteries. Here, we present a new and practical porous membrane with three-dimension (3D) heat-resistant skeleton and high curvature pore structure as a promising separator candidate to facilitate advances in battery safety and performances beyond those obtained from the conventional separators. The unique material properties combining with the well-developed structural characteristics enable the 3D porous skeleton to own several favorable properties, including superior thermal stability, good wettability with liquid electrolyte, high ion conductivity and internal short-circuit protection function, etc. which give rise to acceptable battery performances. Considering the simply and cost-effective preparation process, the porous membrane is deemed to be an interesting direction for the future lithium ion battery separator.

A sandwich‐structured separator based on in situ coated polyaniline on polypropylene membrane for improving the electrolyte wettability in lithium‐ion batteries

“…Moreover, PP@PANI could promote the uniform distribution of the electrolyte and make the interface layer between the separators and the electrodes contact more closely, which is beneficial for restricting the growth of the by-products. 8 The above results indicate that the method is a facile and effective way for the formation and growth of PANI on PP.…”

“…8,[11][12][13] Recently, several strategies have been proposed to improve the electrolyte wettability of polyolefin separators including physical coating and chemical modification. 8,[11][12][13] Recently, several strategies have been proposed to improve the electrolyte wettability of polyolefin separators including physical coating and chemical modification.…”

“…Separators not only act as physical barriers to prevent the directly physical contact between the positive and negative electrodes but also provide passages for lithium-ion transport during the electrochemical process. [6][7][8] Normally, an ideal separator ought to possess characteristics of rich channels, good chemical and mechanical stability, high electrolyte wettability, and so forth. 9,10 The electrolyte wettability of separators could significantly influence ionic transport between the two electrodes, which in turn affect the electrochemical performance of the LIBs.…”

“…Polyolefin porous membrane, one of the most state-ofart separators used in LIBs, usually faces the problem of poor electrolyte wettability because of its intrinsically low surface energy, nonpolar properties, and hydrophobicity. 8,[11][12][13] Recently, several strategies have been proposed to improve the electrolyte wettability of polyolefin separators including physical coating and chemical modification. [14][15][16] For example, Lee et al coated polypropylene (PP) separators with polyvinylidene fluoride (PVDF) copolymer nanofiber using electrospinning technology, which largely improved the electrolyte wettability and the corresponding electrochemical performance of LIBs.…”

Synergistic thermal stabilization of ceramic/co-polyimide coated polypropylene separators for lithium-ion batteries

“…Separators are physical barriers placed between the cathode and anode to protect against internal short-circuits, while simultaneously offering lithium ion pathways through their pores [7,8]. When LIBs are exposed to abnormal conditions such as overcharging, physical crushing, or penetration, an internal shortcircuit is created between the cathode and anode, producing a large exothermic heat, which finally leads to thermal runaway (generating smoke, flame, and finally explosion).…”