Aqueous Zn-ion batteries (ZIBs) have garnered significant interest in recent years due to their potential applications in large-scale stationary energy storage. Early ZIB research has primarily focused on searching for better cathodes and understanding cathodic Zn2+ storage mechanisms. Only very recently has ZIB research shifted to the Zn anode. Here, we report on insights into the interactions between the Zn anode and aqueous Zn-salt electrolytes gained by a systematic investigation of bulk properties of electrolytes, surface properties of the reacted Zn, electrokinetics of Zn/Zn2+ redox reaction, and cycle stability of Zn/electrolyte/Zn symmetrical cells. We found that Zn metal surface, regardless of electrolyte, are always covered by a layer of Zn-containing layered double hydroxides (Zn-LDHs) upon contact with aqueous Zn-electrolytes. We show that “OH- production” pathway resulted from the dissolved oxygen in Zn-electrolytes is the root cause for the Zn-LDHs formation. The electrokinetic studies reveal that Zn/Zn(ClO4)2 interface has the highest exchange current density, while the symmetrical cell tests show that Zn(OTf)2 is the most stable electrolyte for Zn-metal anode.

In this paper, the results of a feasibility analysis are summarized to assess the energy, economic, and environmental benefits of electrification and renewable energy integration for an urban district of Old City, Philadelphia, Pennsylvania. First, the energy demand for the district is reduced through the implementation of cost-effective energy efficiency measures (EEMs) appropriate for Philadelphia’s climate. Then, a combination of distributed generation (DG) systems including wind, photovoltaics, and hydropower are evaluated to determine optimized hybrid systems that meet the energy demand of non-electrified and electrified district. The analysis indicates that the implementation of common and proven EEMs to all the district buildings can reduce its annual energy consumption and CO2 emissions by 13% and 13.8%, respectively. Through cost optimization, a hybrid DG system combining wind and hydropower connected to the grid is found to lower the cost of energy for the non-electrified district to 0.007/kWh, with the added benefit to lower carbon emissions by 10%. Moreover, the analysis considered the case of electrified district which reduces life cycle costs by3.5%. By implementing electrification and EEMs, the electricity usage decreases by 14% and peak demand by 19.5% as well as CO2 emissions by 18%. Through cost optimization to design a hybrid DG system that can meet energy demands of the electrified district, wind and hydropower connected to the grid is found to achieve a cost of energy of0.008/kWh and carbon emissions reduction of 34.9%.

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In this paper, the energy efficiency potential of applying novel dynamic insulation systems to slab foundations is investigated for residential buildings. Specifically, dynamic insulation allows the foundation to change its thermal resistance to reduce both heating and cooling thermal loads compared to static insulation systems. The energy benefits for the dynamic insulation are evaluated using a validated numerical model integrated in state-of-art whole-building simulation tool. Specifically, optimal settings for slab-integrated the dynamic insulation are determined monthly to reduce heating and cooling thermal loads while maintaining thermal comfort for a prototypical house located in representative US climates. The analysis results indicate that the deployment of slab integrated dynamic insulation can reduce heating and cooling energy end-uses by up to 12% (1267 kWh) especially for homes located in cold climates.