A Gum-like Electrolyte Promoting Safety and Performance of Lithium Ion Batteries

锂离子电池的安全性在客户的使用、地面运输和航空运输方面受到越来越多的关注。因此，下一代的这些电池除了高性能之外，还必须更安全。电解液是电池的关键部件之一。它对电池的安全和性能起着非常重要的作用。目前，液体电解质普遍具有较高的离子电导率和良好的界面性能，但存在安全问题。固体聚合物或无机固体电解质本质上是安全的，并表现出优异的机械性能。然而，相比之下，它们具有较低的离子电导率和与电极的界面接触/粘附性差，这限制了它们的广泛实际应用。凝胶电解质通常是液体和固体的结合，是一种很有前途的高性能电解质。但仍存在安全隐患和机械性能不佳等关键问题。因此，这项将各种电解质的安全性和有益特性结合起来的高性能电解质的研究对广泛的工业领域具有重要意义，并进一步有利于清洁能源驱动的市场。该项目的目标是创造一种新型的复合材料，口香糖状（或胶状）材料，用于电解质，具有下一代储能设备（包括各种锂离子电池）所需的性能。这种胶状材料具有以下电解质的关键特性；液体电解质水平离子电导率高，与固体电极保持良好/稳定接触的附着力强，具有良好的机械性能和安全的固体材料水平。该设计是基于三相网络组成或液体组分（即有机液体电解质），热敏颗粒和软基质极性聚合物的固体颗粒组分。优化后的网状结构将使胶状复合材料具有理想的多功能。研究范围包括：(1)研究单个组分在控制关键性能（电导率、机械性能、附着力等）中的作用；(2)黏性复合材料结构性能关系的建立；(3)优选用于高性能电解质的胶状复合材料的组成、结构和性能。该项目的智力优势包括：解决了电解质的关键安全和界面问题，为提高电池的安全性特别是热保护能力引入了新的策略；为功能性复合材料的制备提供了一条新途径。

The safety of lithium ion batteries has seen an increased concern with respect to the customers' usage, ground shipment and air transportation. Therefore, the next generation of these batteries must be safer in addition to high performance. The electrolyte is one of the key components in a battery. It plays a very important role for battery safety and performance. Currently, liquid electrolytes generally possess high ionic conductivity and good interfacial properties but come with safety issues. Solid polymer or inorganic solid electrolytes are essentially safe and show excellent mechanical properties. However, they have low ionic conductivity in comparison and poor interfacial contact/adhesion with electrodes, which limits their broad practical applications. Gel electrolytes are usually a combination of liquid and solid showing a promising type of high-performance electrolyte. However, several critical issues including safety concern and inferior mechanical performance still exist. Therefore, this study on a high performance electrolyte that will combine safety and beneficial properties of various electrolytes is significant and important for broad industry sectors, as well as further benefit the clean energy driven market.The objective of this project is to create a novel composite, gum-like (or gummy) material for electrolytes with the desired performance for next-generation energy storage devices including various lithium ion batteries. This gummy material possesses the following critical properties for electrolytes; high ionic conductivity at the liquid electrolyte level, strong adhesion to maintain good/stable contact with solid electrodes, good mechanical properties and the safety of solid material level. The design is based on a three-phase network composed or liquid component, (i.e. organic liquid electrolyte), solid particle component of thermally sensitive particles and soft matrix polar polymer. The optimized network formation will lead to the desired multi-functionalities for the gummy composite. The scope of the research includes: (1) investigation of the roles of the individual component in controlling the critical properties (conductivity, mechanical properties, adhesion etc.); (2) establishment of structure-property relationships for the gummy composite materials; (3) optimization of the compositions, structures and properties of the gummy composite for high performance electrolyte application. The intellectual merits of this project include: solving critical safety and interfacial problems for the electrolyte, introducing a new strategy for safety improvements in batteries especially thermal-protection capability; leading to a new approach to fabricate functional composite materials.