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，锂离子电池为电机提供动力，从而驱动汽车。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，也是使电动汽车在成本方面商业化的关键障碍。电池最大的问题之一是在充放电期间会产生热量，这需要一个热管理系统，尤其是锂离子电池。此外，电池模块中不均匀或过高的温升会显著降低其寿命和性能。如果电动汽车电池的寿命可以延长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、性能和寿命是非常迫切的。*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(BTM)来应对这些挑战。相变材料的局限性之一是其导热系数低，这会减缓其熔化/冻结速度。更快的熔化/冻结速度是电池热管理的要求。*在本计划中，将开发含有纳米PCM(分散在PCM中的纳米颗粒)浸渍在多孔介质中的复合材料，以加快传热速度。纳米相变材料的一个重要特征是其热物理性质可调。纳米颗粒的加入增加了相变材料的导热系数、粘度、密度，降低了比热，而多孔介质的添加增加了相变材料的传热表面积。因此，本文的研究内容包括：(1)复合纳米相变材料的制备、表征和性能评价；(2)基于纳米相变材料的复合相变储能系统的设计和分析；(3)研究基于复合纳米相变材料的具有紧凑、创新和轻质换热器的相变储能系统在振动环境下的应用。该项目的最终目标是开发用于BTMS的复合相变材料，并将这一知识应用于其他应用领域，如活动服装和面部/身体乳液，以在恶劣环境下保护皮肤区域。虽然这项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本知识是支持实现这一愿景的核心价值。这些知识将是了解新应用程序的窗口，这些应用程序将从这个程序中流出，但可能远远超出它的范围。*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.*****