All-solid-state silicon anodes for next-generation Li-ion batteries

发电和运输部门占加拿大温室气体排放量的三分之一。风能和电动汽车等替代技术正在成为有前途的解决方案，但需要改善成本，性能和关键组件的可持续性-可充电储能。由于其高容量和能量密度，硅阳极和固态电解质是下一代锂离子电池升级的有希望的候选者。然而，硅阳极性能受到几种以前无法克服的退化机制的不利影响。其中之一是在锂化过程中发生的严重体积膨胀，并导致电极内的粉化和电接触损失。此外，当与硅接触时，电解质降解并形成固体电解质界面，该固体电解质界面缓慢分解电解质并导致颗粒之间的电绝缘层的积聚。为了应对这些挑战，滑铁卢大学与ZEN石墨烯解决方案有限公司（ZEN）合作，提出开发全固态电池（SSB）。阳极由封装在ZEN的电解质阻挡石墨烯中的硅组成，该石墨烯提供了体积缓冲的空隙空间。所提出的固体电解质将是一种固体聚合物电解质，其设计有能够与石墨烯良好粘附并实现高导电性的混合聚合物基质。这些修改有可能导致硅阳极几乎没有退化。当与最先进的锂离子阴极相结合时，该团队预计电池总重量将达到320 Wh/kg以上，与当前技术相比，这将提高50%以上。这些改进预计将增加驱动范围并降低电动汽车的成本。空气质量的改善和温室气体排放的预期减少将大大改善加拿大人和那些受气候变化影响不成比例的人的生活质量。拟议的内置加拿大解决方案如果成功，预计将带来显着的就业增长和制造能力，为不断增长的电池市场创造供应链。

The power generation and transportation sectors contribute to one third of Canada's GHG emissions. Alternative technologies such as wind energy and electric vehicles are emerging as promising solutions but require improvements to cost, performance and sustainability of key a component - rechargeable energy storage. Due to its high capacity and energy density, silicon anodes and solid-state electrolytes are promising candidates for the next-generation upgrade of the Li-ion battery. However, silicon anode performance is adversely affected by several previously insurmountable degradation mechanisms. Among these is the severe volume expansion which occurs during lithiation and leads to pulverization and loss of electrical contact within the electrode. Furthermore, when in contact with silicon, the electrolyte degrades and forms a solid electrolyte interface which slowly decomposes the electrolyte and causes the build up of electrically insulating layers between particles. To address these challenges, the University of Waterloo, in collaboration with ZEN Graphene Solutions Ltd (ZEN), proposes to develop an all-solid-state battery (SSB). The anode is composed of silicon encapsulated within ZEN's electrolyte-blocking graphene that provides void space for volume buffering. The proposed solid electrolyte will be a solid polymer electrolyte engineered with a mixed polymer matrix capable of good adhesion to the graphene and achieving high conductivity. These modifications have the potential to lead to a silicon anode with little to no degradation. When coupled to state-of-the-art Li-ion cathodes, the team expects to achieve > 320Wh/kg of total battery weight which is over a 50% improvement compared to current technology. These improvements are expected to increase the drive range and reduce the costs of electric vehicles. The improved air quality and expected reductions in GHG emissions will significantly improve the quality of life of Canadians and those disproportionately affected by climate change. The proposed built-in-Canada solution, if successful, is expected to lead to significant job growth and manufacturing capacity to create a supply chain for the growing battery market.