Sustainable Energy Storage and Conversion: from Performance of Materials to Prototype Development

最近商用电动汽车（EV）产量的增长主要是由于锂离子（Li-ion）电池的发展，锂离子电池为电动机提供动力，从而驱动车辆。截至2016年，全球已售出150万辆电动汽车。电池是驱动电动汽车的关键操作工具，也是电动汽车在成本方面实现商业化的关键障碍。电池最大的问题之一是它在充电和放电期间产生热量，需要热管理系统，特别是对于锂离子电池。此外，电池模块中的不均匀或过度的温度上升显著降低了其寿命和性能。如果电动汽车电池的使用寿命可以增加10年，加拿大的温室气体排放量将减少约56%（nrc cnrc.gc.ca/eng/publications/nrc_pubs/energy_storage/2016/summer_main_article 2016.html）。因此，提高大型电池的安全性、性能和寿命周期是非常必要的。 拟议研究的范围是通过开发使用复合相变材料（PCM）和创新热交换器的被动电池热管理系统（BTMS）来应对这些挑战。PCM的局限性之一是它们的低导热性，这减慢了它们的熔化/冻结速率。更快的熔化/冻结速率是电池热管理的要求。 在这个项目中，将开发含有浸渍在多孔介质中的纳米PCM（分散在PCM中的纳米颗粒）的复合材料，以加快传热速率。纳米相变材料的一个重要特征是其可调的热物理性质。纳米颗粒的加入增加了相变材料的导热系数、粘度、密度，降低了相变材料的比热，而多孔介质的加入增加了相变材料的传热表面积。因此，提出的计划包括（1）复合纳米PCM的制备，表征和性能评估，（2）设计和分析基于复合纳米PCM的潜热热能存储（LHTES）系统，具有紧凑，创新和轻质热交换器，以及（3）研究LHTES系统在BTMS中的应用由于振动。该计划的最终目标是开发用于BTMS的复合PCM，并将这些知识应用于其他应用领域，例如活动服装和面部/身体乳液，以在恶劣环境中保护皮肤区域。虽然该技术的实施是该计划的长期愿景，但推进与该技术相关的所有方面的基础知识是支持实现这一愿景的核心价值。这些知识将成为新应用的窗口，这些应用将从该计划中流出，但可能会远远超出它。根据这一核心价值，该计划的主要范围是培养精通BTMS并拥有适用于不同行业的多学科专业知识的HQP。

The recent growth in commercial electric vehicle (EV) production is primarily due to the development of lithium ion (Li-ion) batteries which power the motor and thus drive the vehicle. As of 2016, 1.5 million electric vehicles had been sold worldwide. The battery is the key operating tool to drive the EV and also the key barrier to making EVs commercially attainable in terms of cost. One of the biggest issues with the battery is that it generates heat during the charge and discharge period, requiring a thermal management system, especially for Li-ion batteries. Further, uneven or excessive temperature rise in a battery module reduces its life and performance significantly. If the lifetime of electric vehicles' batteries could be increased by 10 years, GHG emissions in Canada would be reduced by approximately 56% (nrc cnrc.gc.ca/eng/publications/nrc_pubs/energy_storage/2016/summer_main_article 2016.html). Therefore, improving the safety, performance, and life cycle of the large-scale battery is at great demand. The scope of the proposed research is to address these challenges by developing passive battery thermal management systems (BTMSs) using composite phase change materials (PCMs) and innovative heat exchangers. One of the limitations of PCMs is their low thermal conductivity which slows down their melting/freezing rate. A faster melting/freezing rate is a requirement for battery thermal management. In this program, composite materials containing nano-PCM (nanoparticles dispersed in PCM) impregnated in porous medium will be developed to accelerate the heat transfer rate. An important characteristic of the nano-PCMs is their tunable thermophysical properties. Addition of nanoparticles increases PCM's thermal conductivity, viscosity, density and reduces the specific heat, while addition of porous medium enhances the heat transfer surface area. Therefore, the proposed program includes (1) preparation, characterization, and performance evaluation of composite nano-PCM, (2) design and analyse composite nano-PCM based latent heat thermal energy storage (LHTES) systems with compact, innovative, and light weight heat exchangers, and (3) investigate the application of LHTES systems for BTMS due to vibration. The ultimate goal of this program is the development of composite PCMs for BTMS and apply this knowledge to other application areas such as in active wear apparel and face/body lotion to protect the skin area in  harsh environment. While the implementation of this technology is the long term vision of this program, advancing the fundamental knowledge of all aspects related to this technology is the core value supporting the realization of this vision. This knowledge will be a window to new applications, which will stream from this program but may stretch well beyond it. In line with this core value, a major scope of the program is to educate HQP well-versed in BTMS and possessing a multi-disciplinary expertise applicable in diverse sectors.