A zinc battery electrolyte with a small natural additive has lasted more than 7,000 hours in lab tests, according to a research summary released through EurekAlert. The team, from the Suzhou Institute of Nano-Tech and Nano-Bionics at the Chinese Academy of Sciences, Jiangsu University, Helmholtz Institute Ulm and Karlsruhe Institute of Technology, added L-carnosine, a naturally occurring dipeptide, to the electrolyte. They report that cells with the additive kept running for over 7,000 hours, while cells without it failed after about 680 hours.
Why a zinc battery electrolyte needs fixing
Aqueous zinc metal batteries are attracting growing attention. The summary says they offer inherent safety, low cost and high theoretical energy density. But their practical use is held back by sluggish zinc-ion transport, uneven metal deposition, the growth of dendrites (needle-like zinc deposits) and a side reaction that produces hydrogen.
In ordinary water-based electrolytes, zinc ions are tightly surrounded by water molecules. That creates a high energy barrier for the ions to shed their water coat at the zinc surface. According to the researchers, uneven flow and reactive water lower efficiency, use up electrolyte and shorten battery life.
How L-carnosine changes the electrolyte
Rather than relying only on a protective coating, the team targeted the molecular interactions around the zinc ions. L-carnosine has a permanent dipole moment of 5.34 D, about 2.5 times that of water, so it can compete for the zinc ion and partly replace water in its inner shell. The researchers say this weakens the zinc-water bond and makes it easier for ions to shed their water coat.
The molecule also sticks to the zinc surface and reshapes the layer next to it so that zinc ions move through more evenly, which the team links to smoother, dendrite-free deposition. The best amount was just 10 mmol per litre in a 2 M zinc sulfate electrolyte.
What the zinc battery tests showed
The reported numbers, which come from the researchers’ own lab tests, include:
- An average Coulombic efficiency of 99.72% over 2,000 cycles in zinc-copper cells.
- More than 7,000 hours of stable operation in zinc-zinc symmetric cells, compared with failure after roughly 680 hours without the additive.
- Stability for over 200 hours even at a high depth of discharge of 85.4%.
- A lower barrier to shedding water, from 46.14 to 27.93 kJ per mole, and a zinc-ion transference number that rose from 0.283 to 0.574.
- A full cell with a vanadium oxide cathode that delivered 289 mAh per gram after 500 cycles.
The summary adds that a large-format pouch cell kept approximately 100% of its capacity over 200 cycles and powered a smart electronic device.
The other side: what is not yet shown
This is laboratory research, and the summary itself says further validation under practical operating conditions is needed to establish suitability for scalable energy storage. Symmetric cells are a stress test of the zinc electrode, not a finished product, and 200 cycles on a pouch cell is much shorter than the thousands of cycles a grid battery would be expected to run. The summary gives no cost figures, manufacturing plans or timeline.
There are no direct security concerns in the announcement. On safety, the summary notes that aqueous zinc batteries are inherently safe, though that is a general description and not a test result from this study.
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My view on this zinc battery electrolyte
As a writer, I feel the appeal here is how simple the idea is: one small molecule at a low concentration, instead of a complicated new structure. The jump from 680 hours to more than 7,000 is striking, but I would want to see independent replication, longer pouch-cell tests and cost data before drawing big conclusions.
FAQ: L-carnosine and zinc batteries
What is L-carnosine and why use it in a battery?
L-carnosine is a naturally occurring dipeptide. The researchers used it as an electrolyte additive because its strong dipole lets it compete with water around zinc ions, which they say speeds ion transport and makes zinc deposits more uniform.
How long did the cells last?
According to the summary, zinc-zinc symmetric cells ran for more than 7,000 hours with the additive, compared with failure after about 680 hours without it. A pouch cell kept roughly 100% capacity over 200 cycles.
Are these batteries available to buy?
No. The summary describes laboratory results and says further validation under practical conditions is needed. It gives no commercial plans or timeline.