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The US Interior Department on Thursday blocked mining in part of northeast Minnesota for 20 years, the latest blow to Antofagasta Plc’s Twin Metals copper and nickel mining project but a step officials said is needed to protect the state’s vast network of interconnected waterways.

Interior Secretary Deb Haaland signed an order on Thursday withdrawing 225,504 acres in the Superior National Forest from leasing to mining or geothermal companies through 2043.

In 2019, Chilean miner Antofagasta (LON:ANTO), through its subsidiary Twin Metals, carried out a feasibility study for the project, an underground copper-nickel mine and processing facility along the shores of Birch Lake and the South Kawishiwi River, which lie in the Rainy River watershed.

A coalition of businesses, environmental advocates and outdoor recreation groups in the state of Minnesota went to court challenging a Trump administration’s decision that opened the door to a copper, nickel and platinum project by a wilderness area.

In August 2022, Antofagasta Plc’s Twin Metals subsidiary sued the US government in a bid to revive the proposed Minnesota copper and nickel mine, which Biden administration officials had blocked over concerns it could pollute a major recreational waterway.

Twin Metals asked the US District Court in Washington to restore the leases, which were first granted in 1966 and have been passed between successor companies. No mining has taken place at the site.

The underground mine would, if built, be a major US source of copper and nickel, two metals crucial for the green energy transition. The only existing US nickel mine is set to close by 2025.

Researchers from Tokyo Metropolitan University have demonstrated that electrochemical impedance spectroscopy (EIS) can be a powerful non-destructive tool to study the degradation mechanisms of all-solid-state lithium metal batteries. They studied ceramic-based all-solid-state Li metal batteries prepared by aerosol deposition and heating, identifying the specific interface responsible for the drop in performance. Published in ACS Applied Materials & Interfaces, their work accurately highlights the engineering hurdles that need to be overcome to bring these top-in-class batteries to the market.

Electric vehicles (EVs) are a crucial part of efforts worldwide to cut carbon emissions. And at the heart of every EV is its battery. Battery design remains a key bottleneck when it comes to maximizing driving range and improving vehicle safety. One of the proposed solutions, all-solid-state lithium metal batteries, has the potential to provide higher energy density, safety, and lower complexity, but technical issues continue to hamper their transition into everyday vehicles.

A major problem is the large interfacial resistance between electrodes and solid electrolytes. In many battery designs, both cathode and electrolyte materials are brittle ceramics; this makes it difficult to have good contact between them. There is also the challenge of diagnosing which interface is actually causing problems. Studying degradation in all-solid-state lithium metal batteries generally requires cutting them open: this makes it impossible to find out what is happening while the battery is operating.

A team led by Professor Kiyoshi Kanamura at Tokyo Metropolitan University have been developing all-solid-state Li metal batteries with lower interfacial resistance using a technique called aerosol deposition. Microscopic chunks of cathode material are accelerated towards a layer of ceramic electrolyte material where they collide and form a dense layer.

To overcome the issue of cracks forming on collision, the team coated the chunks of cathode material with a “solder” material, that is, a softer, low melting point material which can be heat treated to generate excellent contact between the newly formed cathode and electrolyte. Their final all-solid-state Li/Li7La3Zr2O12/LiCoO2 cell delivers a high initial discharge capacity of 128 mAh g-1 at both 0.2 and 60 °C and maintains a high-capacity retention of 87% after 30 charge/discharge cycles. This is a best-in-class result for all-solid-state Li metal batteries with ceramic oxide electrolytes, making it all the more important to really get to grips with how they might degrade.

Here, the team used electrochemical impedance spectroscopy (EIS), a widely used diagnostic tool in electrochemistry. By interpreting how the cell responds to electrical signals of different frequency, they could separate out the resistances of the range of different interfaces in their battery. In the case of their new cell, they found that a resistance increase between the cathode material and the solder was the main reason for cell capacity decay. Importantly, they achieved this without tearing the cell apart. They were also able to back this up using in-situ electron microscopy, clearly identifying interface cracking during cycling.

The team’s innovations have not only realized a cutting-edge battery design but highlighted the next steps for making further improvements using a damage-free, widely available method. Their new paradigm promises exciting new advances for batteries in the next generation of EVs.

Future climate policy assigns hydrogen and H2 synthesis products great importance. But how could the demand for hydrogen develop globally?

A new meta-study coordinated by Fraunhofer ISI addresses this question and re-evaluates more than 40 energy system and hydrogen scenarios within the HyPat research project. The study provides statements on the range of possible future developments of hydrogen demand, globally, in the EU, and China until 2050, and differentiates between various demand sectors. The focus is on scenarios with ambitious greenhouse gas reduction targets.

Hydrogen and its synthesis products are globally regarded as important future energy sources that could be used in many different sectors. For example, there is an ongoing controversial debate about the role hydrogen will play in transport in the future, and specifically its use for passenger cars and trucks. There are also potential applications with demand for hydrogen in other sectors, such as industry and buildings.

However, so far, there has been a high degree of uncertainty concerning the future global role of hydrogen, as different studies have arrived at very different results.

Therefore, together with a consortium consisting of Fraunhofer IEG and ISE, the Ruhr University Bochum, Energy Systems Analysis Associates—ESA² GmbH, the German Institute of Development and Sustainability IDOS, the Institute for Advanced Sustainability Studies (IASS) Potsdam, GIZ Deutsche Gesellschaft für Internationale Zusammenarbeit and dena the German Energy Agency, Fraunhofer ISI has conducted a new meta-analysis to address how the global demand for hydrogen could develop in future.

More than 40 current energy system and hydrogen scenarios were re-evaluated, with a particular focus on scenarios featuring ambitious emission reduction targets for greenhouse gases.

Significant increase in the global demand for hydrogen

The majority of studies forecast a significant increase in the global demand for hydrogen, which is particularly marked in the calculations if regions or countries have ambitious goals for greenhouse gas reductions. Global hydrogen demand therefore also depends strongly on the respective regional climate policy and its level of ambition.

The total hydrogen demand worldwide in 2050 ranges between 4 and 11% of global final energy demand. However, there are strong regional differences: For the EU, this share could be as high as 14%, whereas most studies indicate a maximum hydrogen share of 4% of final energy for China. In some cases, the projections of hydrogen demand in the analyzed studies vary considerably, which is why there are significant differences when classifying the role of hydrogen in future energy systems.

Varying relevance of hydrogen in different applications

As far as specific applications are concerned, the biggest demand for hydrogen is expected in the transport sector, according to the study, in both absolute terms and relative to total energy demand. The meta-study calculates an average hydrogen share of 28% for the EU’s transport sector in 2050—based on the total energy demand of the sector—compared to 14% for China and 16% worldwide.

However, transport is also the sector with the widest range and therefore the highest degree of uncertainty concerning future hydrogen use. H₂ synthesis products will be used in areas such as international shipping and aviation, but the possible future use of hydrogen is less clear in other large fields of application such as passenger cars and trucks.

In other sectors, such as industry, it is likely that the quantities of hydrogen demanded will be smaller than in the transport sector, and demand forecasts are lower here. However, hydrogen is considered a no-regret option in the industrial sector, as there are no decarbonization alternatives for numerous industrial applications, for instance, in iron and steel or basic chemicals.

On the other hand, hydrogen use is considered very uncertain in the field of industrial heat generation and for low-temperature heat as well, because of potential alternatives. The meta-study indicates larger regional differences here as well: While the hydrogen share in industry in relation to the total global energy demand ranges between 2 and 9% in 2050, the majority of the analyzed studies forecast between 3 and 16% for Europe, with a maximum share of up to 38%. For China, the projected hydrogen share is 1-4%, with a maximum value of 7%.

Compared to all other sectors, hydrogen plays the smallest role in buildings in all the regions considered. The median share here in most studies is estimated to be less than 2% of building energy in 2050—with very small bandwidths, which suggests the results regarding the low future relevance of hydrogen in this sector are relatively robust. In absolute terms as well, demand in buildings in all regions lags well behind demand in the other sectors.

Prof. Martin Wietschel, who coordinates the research work of the HyPat consortium, estimates the future global significance of hydrogen as follows: “Our evaluations underscore that hydrogen will play an important role in future global climate policy—but will not be the dominant final energy carrier of the future. In order to reduce greenhouse gas emissions globally, measures to save energy and direct electrification based on renewable power, for example, in heat pumps, electric vehicles or heating networks, are seen as the most important levers. On the other hand, hydrogen does play a relevant role in specific applications where other technologies are either technically or economically not feasible.”

Zinc-air batteries, which produce electricity through a chemical reaction between oxygen in the atmosphere and zinc, are considered to be next-generation candidates to meet the explosive demand for electric vehicles instead of lithium-ion batteries. They theoretically meet all required characteristics for next-generation secondary batteries, such as high energy density, low risk of explosion, eco-friendliness (does not emit pollutants), and low cost of materials (zinc and air, which can be easily obtained from nature).

The Korea Institute of Science and Technology (KIST) announced that its research team led by Dr. Joong Kee Lee (Energy Storage Research Center) developed a technology to improve the electrochemical performance of zinc-air batteries by utilizing solar energy, which is emerging as a new research and development area in the secondary battery field.

The battery developed by the research team utilizes a photoactive bifunctional air-electrocatalyst with a semiconductor structure with alternating energy levels, which significantly improves the rates of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) that generate electricity. The photoactive bifunctional catalyst is a compound that accelerates chemical reactions by absorbing light energy and has a improved light absorption ability than conventional zinc-air battery catalysts.

In a zinc-air battery that uses metal and air as the anode and cathode of the battery, OER and ORR must be alternately performed for electrical energy conversion of oxygen as the cathode active material. Therefore, the catalytic activity of the positive electrode current collector, made of carbon material, is an important factor in determining the energy density and overall cell efficiency of zinc-air batteries.

Accordingly, the KIST research team focused on the p-n heterojunction, the basic structural unit of solar cells and semiconductors, as a measure to improve the slow catalytic activity of zinc-air batteries. The goal was to accelerate the oxygen production-reduction process by using the interface characteristics of semiconductors in which electron movement occurs. To this end, a cathode material with a heterojunction bandgap structure was synthesized, with a n-type semiconductor (graphitic carbon nitride, g-C₃N₄) and ap-type semiconductor (copper-doppedZIF-67(ZeoliticImidazolateFramework-67),CuZIF-67).

In addition, an experiment was conducted under real-world conditions without light in order to confirm the commercial potential of the photoactive bifunctional catalyst with a p-n heterojunction structure with alternating energy levels. The prototype battery showed an energy density of 731.9 mAh g_Zn^-1, similar to the best performance of the existing zinc-air battery. In the presence of sunlight, the energy density increased by about 7% up to 781.7 mAh g_Zn^-1 and excellent cycle performance (334 hours, 1,000 cycles), exhibiting the best performance among known catalysts.

Dr. Lee says that “utilization of solar energy is an important part not only in improving the electrochemical performance of secondary batteries but also in realizing a sustainable society. We hope that this technology will become a catalyst that stimulates the development of new convergence technologies in semiconductor physics and electrochemistry, in addition to solving the difficulties of metal-air batteries that are emerging as an alternative to lithium-ion batteries.”

The research was published in Applied Catalysis B: Environmental.