Argonne National Laboratory of the U.S. Department of Energy (DOE) has invented a novel technology that could help fuel the country’s shift from gas-powered vehicles to hybrid and electric power more quickly, at lower cost, and in a more environmentally friendly manner.

Yuepeng Zhang and Kaizhong Gao of the HyMag Magnets team (Image credit: Argonne National Laboratory)

The latest invention, termed HyMag, can prove beneficial to almost any technology that produces power from generators or draws power from electric motors. The former includes standby power for business and offshore wind turbines, while the latter includes battery-powered devices and equipment, like power tools, electric and hybrid vehicles, golf carts, and wheelchairs.

When engineered properly, the gain in the usable flux density of the magnet ranges from 10 to 30%, based on the working temperatures and application, stated HyMag’s inventors Kaizhong Gao and Yuepeng Zhang from Argonne National Laboratory.

This additional efficiency will translate into either more energy produced or you will have less loss. Kaizhong Gao, Group Leader, Nanomaterials, Devices, and Systems, Argonne National Laboratory

A weight-sensitive application like wind turbines can particularly benefit from HyMag , because the c of the technology could result in downsized structures. For instance, stronger magnets would make it viable to decrease the amount of support and weight-bearing materials of the external casings sitting atop direct-drive wind turbines.

The external casings are responsible for over half the weight of a wind tower ranging between 100 and 130 tons. Smaller casings can possibly be developed into taller towers so that stronger winds can be accessed by the turbines.

However, according to Zhang and Gao, even in the absence of an improved design, a 6-MW wind turbine running half the time throughout the year may produce 3 GW more power with a 10% efficiency increase of its generator.

“This will reduce the energy cost of a wind farm and attract more wind power buyers,” stated Gao.

HyMag has won a 2018 R&D 100 award for its novel solution to boosting usable magnetic flux density. The awards, sponsored by R&D Magazine, recognize the 100 most novel technologies of the previous year.

A characteristic of permanent magnets, flux density can be harnessed to generate power.

The higher the flux density you use for power generation, the more energy you generate. You have to have higher flux density in order to have more efficiency. Kaizhong Gao, Group Leader, Nanomaterials, Devices, and Systems, Argonne National Laboratory

In the 1990s, traditional permanent magnets made of boron, iron, and niobium became industrially widespread; however, they have resisted considerable efforts to enhance their performance, informed Zhang, a materials scientist at Argonne National Laboratory.

Permanent magnets are a group of magnets that retain their flux lines and magnetization after being magnetized, conceptually akin to a battery holding electrical charges.

In the past 15 to 20 years, the increase in magnet energy product reached a plateau due to lack of material solution. Yuepeng Zhang, Materials Scientist, Argonne National Laboratory

Investigators have explored numerous ways to enhance the microstructures, composition, and processes of prevalent magnetic materials. Each magnetic material could lead to a slight improvement in the energy product of the magnet. The magnetic flux of a magnet, on the other hand, decays quickly with distance, making the application of magnetic flux inadequate.

Both Gao and Zhang have enhanced the performance of the permanent magnet by integrating hybrid layers of material in a specific way that lowers the flux leakage. In addition, the researchers can customize their invention to particular challenges that might be faced by the private sector.

“If we know the application we can tailor the layers for that application,” Zhang said.

For instance, in electric cars, the maximum allowable temperature of a motor would be about 150 °C (302 °F). However, in the case of wind turbines, the peak temperature can be around 300 °C (572 °F), which requires a more powerful (not demagnetized) magnet design at higher temperatures.

“There are materials that actually have better performance at higher temperatures,” stated Zhang.

The HyMag technology has another attractive feature: for some applications, it may compositionally need up to 90% less heavy rare-earth elements, like gadolinium and dysprosium, by weight, when compared to the regular magnets that exhibit analogous performance.

These elements, largely imported from China, are costly, rare, and hard to recycle; however, the motors in hybrid and electric cars contain about a tenth of a kilogram of dysprosium for each motor.

Industry representatives interested in associating with Argonne National Laboratory in further advancing this technology for certain applications, or to inquire about licensing, can contact [email protected]

The development of Argonne’s HyMag technology was supported by the Department of Energy’s Wind Energy Technology and Advanced Manufacturing offices.