Durable sodium ion batteries

A new and very advanced design for sodium ion cells or batteries solves technical impediments that markedly limited the useful life of batteries of this type and that hindered their large-scale jump to market.

The breakthrough is the work of the team of Jiguang (Jason) Zhang, a pioneer in battery technologies with more than 23 patented inventions in energy storage technology and working at the US Pacific Northwest National Laboratory (PPNL).

Being abundant and cheap, sodium has long been a promising candidate for alternative battery technologies. But the modest lifespan of sodium-ion batteries has hampered their large-scale applications.

In laboratory tests, the new sodium-ion battery designed by Zhang’s team has been shown to have a much greater longevity than all previous ones of its kind.

An ingenious change in the ingredients that make up the battery’s liquid core avoids the performance issues that have plagued sodium-based batteries.

We are therefore faced with the recipe for a battery that one day, surely sooner rather than later, we will see powering electric vehicles and storing solar energy.

Jiguang (Jason) Zhang holds one of the new sodium-ion batteries in his hand. (Photo: Andrea Starr/Pacific Northwest National Laboratory)

Another feature in favor of these sodium ion batteries is that they are environmentally friendly. In addition, they have special safety measures to prevent them from dangerously overheating and causing fires.

In batteries, the electrolyte is the circulating “blood” that keeps energy flowing. The electrolyte is formed by dissolving salts in solvents, giving rise to charged ions that flow between the positive and negative electrodes. Over time, the electrochemical reactions that keep energy flowing slow down, and the battery can no longer recharge properly. In current sodium-ion battery technologies, this degradation process occurs much faster than in comparable lithium-ion batteries.

Zhang, Yan Jin, and Phung Le’s team solved that problem by changing the liquid solution and the type of salt that flows through it to create an entirely new electrolyte recipe. In laboratory tests, the new design proved to be very durable, maintaining 90 percent of its cell capacity after 300 cycles at 4.2 volts, which is far superior to that achieved by most conventional batteries. sodium ions created earlier.

Zhang and his colleagues present the technical details of their new sodium-ion battery in the academic journal Nature Energy, under the title “Low-solvation electrolytes for high-voltage sodium-ion batteries.” (Font: NCYT by Amazings)