Researchers at the Laboratory for Energy Storage and Conversion (LESC), led by Professor Y. Shirley Meng, have achieved a significant breakthrough in energy storage technology by developing the first anode-free sodium solid-state battery. This innovation, a collaboration between the University of Chicago’s Pritzker School of Molecular Engineering and the University of California, San Diego’s Aiiso Yufeng Li Family Department of Chemical and Nano Engineering, marks a major step forward in creating cost-effective, fast-charging, high-capacity batteries for electric vehicles and grid storage.
Grayson Deysher, a PhD candidate at UC San Diego and the lead author of a recent paper published in Nature Energy, emphasized the novelty of this achievement. “While there have been previous advancements in sodium, solid-state, and anode-free batteries, no one has successfully combined these three concepts until now,” Deysher stated.
A New Era in Sustainable Energy
The research introduces a new sodium battery architecture that can cycle stably for hundreds of cycles. By eliminating the anode and utilizing sodium—a more abundant and less expensive alternative to lithium—this battery design offers an affordable and environmentally friendly solution. The solid-state construction further enhances safety and performance.
This advancement is not only a scientific breakthrough but also a critical step toward scaling up battery production, which is essential for transitioning the global economy away from fossil fuels. Professor Meng highlighted the urgency, stating, “To keep the United States running for one hour, we must produce one terawatt-hour of energy. To achieve our goal of decarbonizing the economy, we need several hundred terawatt-hours of batteries, and we need them quickly.”
The Case for Sodium over Lithium
Lithium, the traditional choice for batteries, is becoming increasingly scarce, comprising only about 20 parts per million of the Earth’s crust. In contrast, sodium is much more abundant, making up 20,000 parts per million. The growing demand for lithium-ion batteries in devices like laptops, phones, and electric vehicles has led to soaring prices, further exacerbating the issue.
Moreover, lithium deposits are concentrated in specific regions, such as the “Lithium Triangle” of Chile, Argentina, and Bolivia, which holds over 75% of the global supply. This concentration benefits certain nations in the global push for decarbonization but leaves others at a disadvantage.
Lithium extraction is also environmentally harmful, involving industrial acids or massive water usage in brine extraction. In contrast, sodium, commonly found in ocean water and soda ash mining, is a more environmentally friendly battery material, and the LESC’s research has now made it a powerful one as well.
Innovative Battery Architecture
To match the energy density of lithium batteries, the researchers had to design a new sodium battery architecture. Traditional batteries use an anode to store ions during charging, which then flow through an electrolyte to the cathode, powering devices. Anode-free batteries, however, store ions directly on an electrochemical deposition of alkali metal on the current collector, leading to higher voltage, lower cost, and increased energy density. However, this design poses challenges in ensuring good contact between the electrolyte and the current collector, especially when using solid electrolytes.
The team addressed this by creating a current collector made of aluminum powder, which flows like a liquid. During assembly, the powder was densified under high pressure to form a solid current collector that maintains liquid-like contact with the electrolyte. This innovative approach enables low-cost, high-efficiency cycling, advancing this transformative technology.
Looking Ahead
Deysher expressed optimism about the future of sodium solid-state batteries, which have often been seen as a distant technology. “We hope this paper will encourage further exploration into sodium batteries, showing that they can work well, even outperforming lithium in some cases,” he said.
Professor Meng envisions a future with diverse, clean, and affordable battery options that store renewable energy at the scale required by society. Meng and Deysher have already filed a patent application for their groundbreaking work through UC San Diego’s Office of Innovation and Commercialization.
By Impact Lab
