Enabling the transition to renewable power sources requires further optimization of batteries in terms of energy/power density and cost-effectiveness. Increasing the practical thickness of Li ion battery electrodes not only can improve energy density on cell level but reduces manufacturing cost. However, thick electrodes exhibit sluggish charge-transport kinetics and are mechanically less stable, typically resulting in substandard battery performance compared to the current commercial standards (~50 μm). Here we disclose a novel method based on immersion precipitation by employing a non-solvent to solidify the battery binder, instead of solvent evaporation. This method allows for the fabrication of thick and suitable density electrodes (>100 μm with ultra-high mass loading) offering excellent electrochemical performance and mechanical stability. Using commercial electrode active materials at a remarkable mass-loading of 24 mg cm⁻², the electrodes processed via immersion method are shown to deliver 3.5 mAh cm⁻² at a rate of 2C and operate at rates up to 10C. As additional figure of merit, this method produces electrodes that are both stand-alone and highly flexible, which have been evaluated in flexible full-cells. Furthermore, via immersion precipitation the commonly used more toxic N-Methyl-2-pyrrolidone can be supplanted by environmentally benign dimethyl sulfoxide as solvent for processing electrode layers.

The world's future energy supply will include intermittent renewable sources, such as solar and wind power. To guarantee reliability of supply, fast-reacting, dispatchable and renewable back-up power plants are required. One promising alternative is parked and grid-connected hydrogen-powered fuel cell electric vehicles (FCEVs) in "Vehicle-to-Grid" systems. We modified a commercial FCEV and installed an external 9.5 kW three-phase alternating current (AC) grid connection. Our experimental verification of this set-up shows that FCEVs can be used for mobility as well as generating power when parked. Our experimental results demonstrate that present-day grid-connected FCEVs can respond to high load gradients in the range of -760 % s^-1 to + 730 % s^-1, due to the parallel connection of the high voltage battery and the fuel cell stack. Virtual power plants composed of multiple grid-connected FCEVs could perform higher power gradients than existing fast-reacting thermal power plants with typical power gradients of 1.67 % s^-1. Hydrogen consumption in 9.5 kW AC grid-connected mode was 0.55 kg h^-1, resulting in a Tank-To-Grid-AC efficiency of 43% on a higher heating value basis (51 % on a lower heating value basis). Direct current to alternating current efficiency was 95 %.

This paper presents the results of a demonstration project, including building-integrated photovoltaic (BIPV) solar panels, a residential building and a hydrogen fuel cell electric vehicle (FCEV) for combined mobility and power generation, aiming to achieve a net zero-energy residential building target. The experiment was conducted as part of the Car as Power Plant project at The Green Village in the Netherlands. The main objective was to assess the end-user's potential of implementing FCEVs in vehicle-to-grid operation (FCEV2G) to act as a local energy source. FCEV2G field test performance with a Hyundai ix35 FCEV are presented. The car was adapted using a power output socket capable of delivering up to 10 kW direct current (DC) to the alternating current (AC) national grid when parked, via an off-board (grid-tie) inverter. A Tank-To-AC-Grid efficiency (analogous to Tank-To-Wheel efficiency when driving) of 44% (measured on a Higher Heating Value basis) was obtained when the car was operating in vehicle-to-grid (V2G) mode at the maximum power output. By collecting and analysing real data on the FCEV power production in V2G mode, and on BIPV production and household consumption, two different operating modes for the FCEV offering balanced services to a residential microgrid were identified, namely fixed power output and load following. Based on the data collected, one-year simulations of a microgrid consisting of 10 all-electric dwellings and 5 cars with the different FCEV2G modes of operation were performed. Simulation results were evaluated on the factors of autonomy, self-consumption of locally produced energy and net-energy consumption by implementing different energy indicators. The results show that utilizing an FCEV working in V2G mode can reduce the annual imported electricity from the grid by approximately 71% over one year, and aiding the buildings in the microgrid to achieve a net zero-energy building target. Furthermore, the simulation results show that utilizing the FCEV2G setup in both modes analysed, could be economically beneficial for the end-user if hydrogen prices at the pump fall below 8.24 €/kg.

In this paper, a framework is presented for the evaluation of smart grid environment which is called the three-layer model. This three-layer model comprises three specific categories, or 'layers', namely, the stakeholder, market and technologies layers. Each layer is defined and explored herein, using an extensive literature study regarding their key elements, their descriptions and an overview of the findings from the literature. The assumption behind this study is that a solid understanding of each of the three layers and their interrelations will help in more effective assessment of residential smart grid pilots in order to better design products and services and deploy smart grid technologies in networks. Based on our review, we conclude that, in many studies, social factors associated with smart grid pilots, such as markets, social acceptance, and end-user and stakeholder demands, are most commonly defined as uncertainties and are therefore considered separately from the technical aspects of smart grids. As such, it is recommended that, in future assessments, the stakeholder and market layers should be combined with the technologies layer so as to enhance interaction between these three layers, and to be able to better evaluate residential smart energy systems in a multidisciplinary context.