Polyurethane-Based Elastomeric Polymer Electrolyte for Lithium Metal Polymer Cells with Enhanced Thermal Safety

Abstract

A large number of applications such as mobile electronics and electric vehicles requires rechargeable batteries with high energy density and enhanced safety. To achieve these goals, lithium metal batteries employing solid-state electrolytes have become common despite the safety concerns associated with lithium metal. Polymer electrolytes have been studied as a solution for enhancing the safety of lithium metal batteries because they are non-volatile, non-flammable, and suppress the growth of lithium dendrites. In this study, highly elastic polyurethane (PU)-based polymer electrolytes were prepared in the form of thin flexible films, and their electrochemical characteristics were investigated. To improve the ionic conductivity, non-volatile and non-flammable 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide was added as a plasticizing additive to the polymer electrolyte. The cell assembled using a Li anode, PU-based elastomeric polymer electrolyte and composite LiNi0.6Co0.2Mn0.2O2 cathode exhibited stable cycling performance by suppressing the growth of lithium dendrites as well as maintaining good interfacial contacts between electrolyte and electrodes during repeated cycling.

Effect of fillers on the microphase separation in polyurethane composites: A review

“…Although several reviews have summarized testing methods for PU microphase separation, 6,23 there is currently no summary and discussion of the effects of filler types and properties on PU microphase separation. Summarizing these different views is of great significance for a deeper understanding of the mechanism by which fillers affect microphase separation degree and for the study of new functional PU composite materials (such as multi‐stimulus responsive shape memory materials and polymer electrolytes in lithium batteries) 5,24–28 …”

“…Summarizing these different views is of great significance for a deeper understanding of the mechanism by which fillers affect microphase separation degree and for the study of new functional PU composite materials (such as multi-stimulus responsive shape memory materials and polymer electrolytes in lithium batteries). 5,[24][25][26][27][28] In this review, we classify commonly used fillers into three categories according to their shapes: spherical fillers, fibrous fillers, and layered fillers. We discuss and summarize the effects of different fillers and their characteristics on the microphase separation of PU.…”

Disulfide bond-embedded polyurethane solid polymer electrolytes with self-healing and shape-memory performance

“…[29][30][31] Flexible polyurethane (PU) has been identified as an ideal matrix for fabricating self-healing and shape-memory materials due to its structural designability, 32 robust mechani-cal strength, 33 and good compatibility with other kinds of polymer matrices or inorganic fillers. [34][35][36] The soft segment of PU is mainly composed of polar polyether, 37 polyester, 38 or polycarbonate, which is favorable for the transport of lithium ions, 39 and the presence of hard segments provides excellent mechanical properties. 40,41 In addition, the hydrogen bonding interaction between the -NH and -CvO groups in the hard segment further endows the polymer material with selfhealing properties.…”

Triallyl cyanurate copolymerization delivered nonflammable and fast ion conducting elastic polymer electrolytes

“…22 Elastic polymer electrolytes have been developed recently to alleviate the volume changes of metallic lithium anodes. [23][24][25][26][27][28][29][30] Several kinds of elastic polymer matrices, such as, polyurethane, polysiloxane and poly(propylene oxide) are also explored. As reported by Lee et al, 31 the plastic-crystalembedded elastomer electrolyte exhibits both superior mechanical elasticity and high ionic conductivity.…”