STTR Phase I: Carbon-encapsulated sulfur cathodes for next generation batteries

这项小型企业技术转移（STTR）第一阶段项目的更广泛影响/商业潜力是实现下一代锂电池技术，这是向增加可再生能源部署过渡不可或缺的一部分。特别是，该项目有可能克服电动汽车（EV）广泛采用的障碍，包括电池容量限制、高电池成本和供应链问题。目前，电动汽车占据了锂电池市场的绝大部分份额，随着未来几年电动汽车部署的增加，这一市场份额可能会大幅增加。上述锂电池技术的问题必须得到解决，以实现电动汽车的预期潜力。这个STTR项目旨在推进一种生产关键电池组件的新工艺-电池阴极。这个STTR一期项目建议使用一种新的阴极生产方法来提高硫化锂（Li-S）电池的可行性。硫化锂电池的重量能量密度是现有锂电池的两倍以上，但锂硫电池的循环寿命很短，因为在循环过程中阴极形成的多硫化物保留率很差。如果这些多硫化物能够从阴极扩散出去，它们就会与电解质和阳极发生一些有害的反应和相互作用，从而损坏电池。该项目旨在通过在碳支架内封装来保留阴极内的硫和多硫化物。具体研究将包括评估碳支架可以达到的最大硫负荷，碳支架可以导电的程度，用含硫碳支架构建阴极，以及测试由这些阴极构建的电池的性能。此外，还将对阴极技术进行技术经济分析，以评估其在当前锂电池技术背景下的潜力。预期的结果包括证明阴极技术的技术和经济可行性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) Phase I project is to enable next-generation lithium battery technologies that are integral in transitioning toward increased renewable energy deployment. In particular, the project has the potential to overcome obstacles to widespread electric vehicle (EV) adoption including battery capacity limitations, high battery cost, and supply chain issues. EVs currently account for a significant majority of the lithium battery market and this market share will likely increase dramatically as deployment of EVs increases in coming years. The aforementioned issues with lithium battery technologies must be addressed for EVs to reach their envisioned potential. This STTR project seeks to advance a novel process for the production of a critical battery component – the battery cathode. This STTR Phase I project proposes to advance lithium sulfide (Li-S) battery viability using a novel approach to cathode production. Lithium sulfide batteries can provide more than double the gravimetric energy density of current lithium batteries, but Li-S batteries suffer from a short cycle life due to the poor retention of polysulfide species which are formed at the cathode during cycling. If these polysulfide species are able to diffuse away from the cathode, they participate in several detrimental reactions and interactions with both the electrolyte and anode, and the battery is damaged. This project seeks to retain the sulfur and polysulfides within the cathode using encapsulation within a carbon scaffold. Specific research will include assessments of the maximum sulfur loading that can be achieved in the carbon scaffold, the extent to which the carbon scaffold can be rendered electrically conductive, construction of cathodes from the sulfur-loaded carbon scaffold, and tests of the performance of batteries constructed from these cathodes. In addition, a technoeconomic analysis of the cathode technology will be performed to assess its potential in the context of current lithium battery technology. Expected outcomes include demonstrated technical and economic viability of the cathode technology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.