Prototype development and techno-economic analysis of electrochemical energy storage systems

Abstract

The US has to implement decarbonization efforts at twice the current rate to achieve its net-zero emission target by the year 2050. Electrochemical energy storage systems are expected to play an important role in this effort to manage the temporal and spatial mismatch in variable renewable energy (VRE) sources availability and the energy demand. Despite the prevalence of Li-ion batteries, this technology alone cannot be a panacea for all our energy storage needs, particularly for applications such as long-duration energy storage for the electric power sector and clean energy carriers for other energy sectors. In this study, three technologies with low energy capacity costs to meet the aforementioned demands were evaluated and their potential roles in the future decarbonized energy sector was identified.

First, the feasibility of a new flow battery chemistry, namely, Zn-MnO2 semi-solid flow battery (SSFB) was evaluated for energy storage applications in the electric power sector. Despite the low energy capacity cost of Zn-MnO2 SSFB, stringent pumping requirements compared to an all-liquid flow battery may limit their techno-economic feasibility. To understand the trade-off between electrochemical performance, rheological performance, and cost, experimental analysis and bottom-up cost analysis was performed. The high power required for pumping was found as a bottleneck for the power capacity costs of the SSFB system. However, with the adoption of appropriate strategies, the system cost can be made competitive with Li-ion battery systems for discharge durations over a day.

Secondly, the feasibility of Zn-air and Al-air battery technologies was evaluated using techno-economic analysis. Three important cell performance parameters were studied to understand their sensitivity towards the levelized cost of storage of the metal-air batteries in comparison to existing Li-ion technology. Technologies such as Zn-air batteries was found to require collective improvements in all three cell performance parameters (areal capacity, cycle life, and efficiency) to be competitive with existing solutions like Li-ion battery.

Thirdly, we evaluated the techno-economic feasibility of alternative hydrogen storage systems such as liquified hydrogen and liquid organic hydrogen carrier (LOHC) to meet the energy demand in both electric power and other sectors using a hydrogen supply chain optimization model. We found that these ultra-low energy capacity cost technologies can play an important role in meeting the seasonal demand in both energy sectors. Additionally, the low discharge power capacity cost of LH2 was found to add significant value as short-burst energy release for the electric power sector similar to present-day liquified natural gas.