Jun 20 2019
As revolutionary as electric vehicles are, they are still susceptible to an Achilles heel — the very source that provides them power.
One of the typical types of batteries fitted in electric vehicles, lithium-ion batteries (Li-ion batteries) is vulnerable to catching on fire or bursting because of a crash or any other major impact applied onto the vehicle. The impact causes the internal short-circuit of electrodes. The small fire can spread all through the battery and to other areas of the car through "thermal runaway."
“尽管已经对电池电池的热管理进行了重大努力，但在最近的电动汽车事故中，电池火和爆炸引起了公众的重大关注，”Yu Zhu博士说，聚合物科学副教授欧洲杯线上买球阿克伦大学（UA）。"In most cases, the battery ignited when it was not operated under normal use, such as through a large external impact, or crash."
朱和他在UA的聚合物科学与聚合物工程学院的研究生团队的目的是通过开发剪切厚的电解质来增强锂离子电池的安全性，这种物质在撞击过程中可欧洲杯线上买球能会变厚，放置在电池的阳极和电池的阳极之间抗撞击的阴极，因此不会在碰撞时引起大火或爆炸。在通常的情况下，新颖的电解质保持柔软。
该团队的研究由朱的博士学位领导。学生Kewei Liu最近在电源杂志: "A shear thickening fluid based impact resistant electrolyte for safe Li-ion batteries."
在用于电动汽车的锂离子电池中，阴极和阳极由非常柔软的膜和液体电解质分开。只需用固体对应物代替液体电解质仍然是一项艰巨的任务，因为两个电极都是多孔的，并且需要液体来填充毛孔并进行接触。我们的想法是，您仍然可以在正常情况下使用液体样电解液，但是液体可以改善其自身的机械强度。因此，我们开发了一种剪切厚的电解质。
Yu Zhu博士，UA聚合物科学副教授欧洲杯线上买球
Imagine it to be like a starch and water mixture. When one puts their hand into it and slowly stirs the starch and water, a very little resistance is felt. However, if the stir rate is increased, one will clearly feel much more resistance. Actually, it is possible for a bowling ball to bounce off the surface of a water and cornstarch mixture, which acts like a solid during impact.
A liquid having such properties is referred to as a dilatant, a type of non-Newtonian fluid. If an electrolyte is also a dilatant, it will stop the battery from short-circuiting under external impact. However, creating a shear-thickening electrolyte is a lot more difficult than blending cornstarch and water, as the composition of the electrolyte is complex containing different ions, solvents, and numerous additives.
“在我们的初步研究中”Zhu said,“我们证明了改良的低成本玻璃纤维填充剂可以产生我们要寻找的剪切厚的电解质，该电解质与商业锂离子电池兼容，并显示出改善的抗冲击力性。”
朱团队的视频以影响标准液体电解质和剪切厚的电解质的不同速度显示子弹。剪切厚的电解质吸收了动能，并大大减速了运动子弹。
与常规的液体电解质相比，剪切厚的电解质不会显着降低锂离子电池的性能.During an impact, the shear-thickening electrolyte will immediately behave like a solid and generate larger force to resist external impact because of the shear-thickening effect. This solution is complementary to external thermal management system of the battery pack, which often falls short in response to the abrupt impact.
Yu Zhu博士，UA聚合物科学副教授欧洲杯线上买球
朱说，关于增强锂离子电池的研究是非常新的，尤其是用于电动汽车的使用。他继续说，剪切厚的电解质可以采用其他新颖的应用，例如在防弹储能设备中。