Volume 7 Issue 3, March 2022

Anion-exchange membrane fuel cells offer the prospect of low-cost components thanks to their alkaline environment, yet they are plagued by carbonation of the electrolyte caused by the CO₂ present in the feed air. Now, an electrochemical method for CO₂ scrubbing using a membrane with mixed ionic–electronic conductivity offers a potential remedy.

Perovskite and organic semiconductors can be combined to make tandem solar cells but, to date, their efficiency has hovered around 20%. Now, researchers demonstrate a 23.6% tandem by reducing interfacial defects to improve the perovskite cell’s voltage and developing an ultrathin interconnection layer.

Using metal oxide nanoparticle additives can protect platinum group metal-free electrocatalysts from the attack of oxidizing radicals. Fuel cells with these radical scavengers have better durability than fuel cells without the scavengers.

Electrochemical charge storage in a confined space is often interpreted as either electrostatic adsorption or Faradaic intercalation. Here the authors propose that the storage mechanism is a continuous transition between the two phenomena depending on the extent of ion solvation and ion–host interaction.

The efficiency of perovskite/organic tandem solar cells is limited by losses in the open-circuit voltage and at the interconnecting layer. Now, Chen et al. develop a defect passivation strategy and a thin indium zinc oxide interlayer which lead to an efficiency as high as 23.6%.

Hydroxide exchange membrane fuel cells (HEMFCs) can make use of some relatively cheap components due to their alkaline environment, but face the problem of CO₂ in the air feed impeding performance. Here, the authors demonstrate a hydrogen-powered shorted electrochemical cell that effectively removes CO₂ from air streams for use in HEMFCs.

High-temperature polymer electrolyte membrane fuel cells are promising for heavy-duty vehicle applications, but strides in performance are needed to improve their commercial viability. Here it is demonstrated that protonating phosphonic acid electrodes greatly enhances power density and durability.

Advanced nuclear reactors may lead to a significant reduction in the cost of nuclear energy. Duan et al. incorporate a wide range of potential advanced nuclear costs in their assessment of future decarbonization options and find areas where nuclear can support wind and solar.

The performance of thermal energy storage based on phase change materials decreases as the location of the melt front moves away from the heat source. Fu et al. implement pressure-enhanced close contact melting to retain high energy density and power density.

Low-cost catalysts for oxygen reduction, such as Fe–N–C materials, often suffer from poor stability in fuel cells due to the generation of oxidizing radical species. Here the authors locate Ta–TiO_x additives in the vicinity of Fe–N–C catalysts and show that they can successfully scavenge radicals, improving durability.

As renewable energy technology costs fall, there are increasing calls to remove policy support. Pahle et al. examine the impacts of such a move combined with higher interest rates in the European Union, and find that resulting higher financing could double long-term carbon prices and halve the rate of capacity deployment in the next 15 years.