Lithium batteries are causing serious damage to our ecosystems, but not because of their composition. We still do not know how to dispose of them. Since we are not learning, a group of scientists decided to try with the most abundant element in nature—and it has worked.
Water-based batteries are not science fiction: they’re real, and they’ve been created
For decades, lithium-ion batteries have been the dominant rechargeable battery technology for consumer electronics and electric vehicles. But lithium’s high cost and supply constraints have limited broader adoption of electric vehicles and renewable energy storage.
Now, a novel battery design using water instead of expensive lithium promises to disrupt the energy storage landscape. Researchers have developed fully functional aqueous batteries that replace lithium with abundant, inexpensive materials like manganese, zinc, and metal oxides.
The electrolyte is simply water mixed with salt. This makes them far cheaper to produce while avoiding the raw material bottlenecks of lithium-ion. And because they don’t require heavy metals or flammable materials, water-based batteries are inherently safer and easier to recycle.
Major companies like IBM and startup Aquion Energy have proven water-based batteries can be mass produced and integrated into real world systems. While still an emerging technology, their potential to store renewable energy cheaply and safely makes aqueous batteries one of the most promising battery innovations today.
We may soon see water replacing lithium as the foundation of our batteries and enabling the next generation of electric vehicles and grid storage. The age of water-based batteries is no longer just science fiction.
The company that has developed the first water-based batteries
A Boston-area startup called Alsym Energy is pioneering a new type of rechargeable battery based on water instead of lithium. Alsym has developed an innovative energy storage technology using inexpensive, readily available materials that performs on par with lithium-ion batteries.
The company emerged from stealth mode in 2022 after several years developing its proprietary water-based battery chemistry. Alsym’s CEO Mukesh Chatter explains their motivation is to create affordable high-performance batteries to enable wider deployment of renewable energy solutions, especially in developing countries.
Unlike lithium-ion batteries, Alsym’s water-based batteries avoid expensive materials like cobalt and lithium that have supply chain and ethical mining issues. The design utilizes safer, non-toxic materials like manganese, metal oxides, and water.
Alsym states their water batteries have “lithium-like performance,” matching lithium-ion on metrics like energy density and cycle life. But they avoid the fire risk of lithium batteries, opening additional applications like maritime shipping.
The company is poised to start beta testing with customers in 2023, with plans to reach high-volume manufacturing as early as 2025. Alsym aims to first make renewable energy storage affordable in low-income regions that lack access to electricity.
How did they manage to manufacture the water-based batteries and who did it?
Alsym Energy’s novel battery uses zinc, manganese oxide, and water as its key components. The battery has a zinc anode and a manganese oxide cathode suspended in a water-based electrolyte.
When the battery discharges, the zinc anode oxidizes to Zn2+ ions which dissolve into the electrolyte. The manganese oxide cathode is reduced to Mn2O3 by taking electrons from the external circuit. Charge is transported between the electrodes by H+ ions in the electrolyte.
On charge, the reactions reverse – Zn2+ ions are reduced back to zinc metal at the anode, while manganese oxide reforms at the cathode by taking electrons from the external circuit. This zinc-manganese redox chemistry enables the battery to store and release charge reversibly.
The water-based electrolyte is a key enabler of the battery’s safety, as it is non-flammable unlike standard lithium-ion electrolytes. It also dissolves the zinc active material, allowing high zinc utilization. The battery operates at near-neutral pH, avoiding corrosion issues.
It is clear that water-based batteries will mark a before and after, although there are still some issues to be resolved. How will they determine the energy efficiency of a household appliance? Will it be possible to use them in cars? There is still a long way to go, but the most important thing has been done, and it seemed impossible.
