A new battery design could help integrate renewable energy into the nation’s grid easily and cost-effectively, using earth’s abundant metals, according to a study just published in . energy storage materialA research team led by the Department of Energy’s Pacific Northwest National Laboratory found that a new design of grid energy storage batteries built with low-cost metals sodium and aluminum could lead to a safer, more scalable fixed energy storage system. Proven to provide a way.
Materials scientist Guosheng Li said: Principal Investigator of the study at PNNL. “This new sodium-based chemistry has similar performance above 100 °C. [212 °F] Lower temperatures than commercially available high temperature sodium battery technology while using more earth-abundant materials. “
Provides more energy storage
Imre Gyuk, Energy Storage Program Director, Department of Electricity, DOE, which sponsored the study, said, “This battery technology is built with low-cost materials available domestically and meets our nation’s clean energy goals. We are one step closer to achieving it.”
A new sodium-based molten salt battery uses two different reactions. The team previously reported a neutral molten salt reaction. New discoveries show that this neutral molten salt reacts further to an acidic molten salt. Importantly, this second acidic reaction mechanism of his increases the capacity of the battery. Specifically, after 345 charge/discharge cycles at high current, this acidic reaction mechanism retained 82.8% of the peak charge capacity.
The energy a battery can deliver in the discharge process is called its specific energy density, expressed in “watt-hours per kilogram” (Wh/kg). The battery is in its early stages, or “coin cell” testing, but researchers speculate it could have practical energy densities of up to 100 Wh/kg. In comparison, the energy density of lithium-ion batteries used in commercial electronics and electric vehicles is around 170-250 Wh/kg. However, the new sodium-aluminum battery design has the advantage of being cheaper and easier to manufacture in the United States from much more abundant materials.
“With optimization, we expect the specific energy density and life cycle to be even higher and longer,” added Li.
Sodium batteries show their mettle
In fact, PNNL scientists worked with colleagues at US-based renewable energy pioneer Nexceris to assemble and test the battery. Through its new business, Adena Power, Nexceris supplied his PNNL with a patented solid sodium-based electrolyte to test battery performance. This critical battery component allows sodium ions to move from the negative (anode) to the positive (cathode) side of the battery during charging.
“The main goal of this technology is to enable a low-cost daily transfer of solar energy to the grid for 10 to 24 hours, energy storage systems and related technologies. It’s the perfect place to start thinking about integrating into the grid to provide true grid resilience from renewable sources such as wind and solar power.”
Sprenkle was part of the team that developed this battery’s new flexible design. We also changed the battery from a traditional tubular shape to a flat, expandable one that can be stacked and expanded more easily as technology evolves from coin-sized batteries to larger batteries. Demonstration size of the grid scale. More importantly, this flat cell design allows for increased cell capacity simply by using a thicker cathode. The researcher took advantage of this in this work, where under laboratory conditions he demonstrated his triple-capacity cell with a sustained discharge of 28.2 hours.
Most current battery technologies, including lithium-ion batteries, are suitable for short-term energy storage. Meeting the demand for energy storage for 10+ hours requires the development of new, low-cost, safe and long-lasting battery concepts beyond current state-of-the-art battery technology. This study provides a promising lab-scale demonstration towards that goal.
Variations on the theme of grid resilience
The ability to store energy produced by renewables and release it to the grid when needed has fueled rapid advances in battery technology, with many new designs competing for attention and customers. Each new variation must meet the demands of each niche application. Some batteries, such as PNNL’s freeze-thaw battery design, can store seasonally generated energy for months at a time.
Compared to seasonal batteries, this new design is particularly suitable for short to medium term grid energy storage over 12 to 24 hours. This is a variation of the so-called sodium metal halide battery. A similar design using a nickel cathode as part of the system has been shown to be effective on a commercial scale and is already commercially available.
“We eliminated the need for nickel, a relatively rare and expensive element, without sacrificing battery performance,” said Li. “Another advantage of using aluminum over nickel is that aluminum cathodes charge more rapidly, which is important for enabling the longer discharge times demonstrated in this study.”
Having reached this milestone, the team is focusing on further improvements to extend the discharge period. This could significantly increase the flexibility of the grid to incorporate more renewable energy sources.
It also operates at lower temperatures, so it can be manufactured with cheaper battery materials instead of requiring the complex and expensive components and processes of traditional high-temperature sodium batteries, said PNNL battery experts and research co-workers. Author David Reed says: .
More grid energy storage at lower cost
By 2023, the state-of-the-art in grid energy storage using lithium-ion batteries will have about four hours of energy storage capacity, Sprenkle said. “This new system can significantly increase the energy storage capacity if we can meet the expected cost targets in materials and manufacturing,” he added.
As part of the study, the researchers estimate that a sodium-aluminum battery design based on inexpensive raw materials could cost as little as $7.02 per kWh of active material. They predict that optimization and increased real energy densities will further reduce this cost. This promising low-cost, grid-scale storage technology could enable intermittent renewable energy, such as wind and solar power, to contribute more dynamically to national power grids.
Study co-author Neil Kidner, president of sodium solid-state battery manufacturer Adena Power, is working with PNNL to advance sodium-based battery technology. “This study shows that our sodium electrolyte works not only with our patented technology, but also with sodium-aluminum battery designs,” he said. “We look forward to continuing our partnership with the PNNL research team to advance sodium battery technology.”
Original: New sodium, aluminum battery aims to integrate renewable energy for grid resilience
Than: Pacific Northwest National Laboratory
