SusChem: Manganese oxide supercapacitor charging/discharging mechanisms to capture energy using capacitive mixing (CapMix)

[1603635]戈尔斯基，克里斯托弗a .处理废水目前消耗了全国总能源需求的2-5%，废水处理厂和工业场所的可再生能源以盐度梯度和废热的形式提供这种能源的机会很大。这项工作的目标是探索一种新的概念，利用锰氧化物的充电和排放来发电，在现场，在污水处理厂。这种方法使用低成本和无毒的材料，并且能够以浓缩盐溶液的形式储存能量，当有能源需求时可以使用。由于低盐度废水与高盐度海水混合释放的熵能，全球排放到海水中的处理废水释放的能量高达19吉瓦。在美国，工业场所和发电厂有超过1000千兆瓦的废热，这些废热可用于通过蒸发或蒸馏过程产生热量产生盐度梯度。一种从这两种来源产生电能的新方法是使用电极，当暴露在不同盐度的溶液中时，电极会发生电容性和/或伪电容性氧化还原反应。这种方法被称为电容混合或CapMix，可以使用低成本和无毒的材料。当CapMix与废热源结合使用时，它可以以浓缩溶液的形式储存能量，当有能源需求时可以使用。CapMix工艺比以前探索的捕获盐度梯度能量的方法（如压力延迟渗透和反电渗析）更有优势，因为它们不需要昂贵的膜。CapMix工艺直到最近才被发明和研究，因此相关反应的特征仍然很差，也没有被优化用于能源生产。这项工作的目标是确定锰氧化物充放电机制作为水溶液条件和锰氧化物结构和粒度的函数，并利用这些信息来优化CapMix电池中锰氧化物电极的功率密度。为了实现这一目标，pi将追求三个基本研究问题：1)Mn氧化物在氯化钠溶液中充电的机制是什么，它如何随着Mn氧化物结构和粒径的变化而变化？2)将盐从氯化钠改为与热生成盐度梯度相关的盐是否会改变锰氧化物的充放电机制？如果有，怎么做？3)当锰氧化物和电池设计优化时，自然和热生成盐度梯度的最大可实现功率密度是多少？为了交流这项研究并帮助教育年轻科学家，研究人员将通过宾夕法尼亚州立大学外展和科学参与办公室每年为大约100名年轻女性开发和举办为期一天的研讨会。这些努力以及其他努力将通过研究和推广活动解决从可再生、碳中性来源获取能源的国家需求，从而造福社会。

1603635Gorski, Christopher A.Treating wastewater currently consumes 2-5% of the total national energy demand and there are tremendous opportunities for providing this energy from renewable on-site sources at wastewater treatment plants and industrial sites in the form of salinity gradients and waste heat. The goal of the proposed work is to explore a new concept using charging and discharging of manganese oxide to generate electricity, on site, at wastewater treatment plants. This approach uses low-cost and non-toxic materials and will be able to store energy in the form of a concentrated salt solution which can be used when there is an energy demand.Treated wastewater discharged into seawater releases as much as 19 gigawatts globally due to entropic energy released through mixing of the low-salinity wastewater with high-salinity seawater. Over 1000 gigawatts GW of waste heat is available in the U.S. at industrial sites and power plants, which can be used to produce heat-generated salinity gradients through evaporative or distillation processes. A new approach for generating electrical energy from both these sources is using electrodes that undergo capacitive and/or pseudo-capacitive redox reactions when exposed to solutions with different salinities. This approach, referred to as Capacitive Mixing or CapMix, can use low-cost and non-toxic materials. When CapMix is used in conjunction with waste heat sources, it can store energy in the form of a concentrated solution that can be used when there is an energy demand. CapMix processes are advantageous over previously explored methods to capture salinity gradient energy, such as pressure retarded osmosis and reverse electrodialysis, because they do not require membranes that are often prohibitively expensive. CapMix processes have only recently been invented and investigated, and consequently the relevant reactions that occur remain poorly characterized and have not been optimized for energy production. The goal of the proposed work is to determine Manganese (Mn) oxide charging and discharging mechanisms as a function of aqueous solution conditions and Mn oxide structure and particle size, and to use this information to optimize the power densities of Mn oxide electrodes in CapMix cells. To reach this goal, the PIs will pursue three fundamental research questions: 1) What is the mechanism of Mn oxide charging in sodium chloride solutions, and how does it change as a function of Mn oxide structure and particle size? 2) Does changing the salt from sodium chloride to those relevant to heat-generated salinity gradients alter the Mn oxide charging and discharging mechanisms? If so, how? 3) What are the maximum achievable power densities for natural and heat-generated salinity gradients when the Mn oxide and cell deign are optimized? To communicate this research and help to educate young scientists, the researchers will develop and conduct a 1-day workshop for approximately 100 young women each year through the Penn State Outreach and Scientific Engagement Office. These efforts, and others, will benefit society by addressing the national need to capture energy from renewable, carbon-neutral sources through research and outreach activities.