Crab Shells Massively Improve Zinc-Ion Batteries

In the fast-moving world of battery research, scientists are constantly on the lookout for innovative materials with the right properties to help improve energy storage. Meanwhile, batteries are in greater demand than ever as production of EVs and renewable energy projects ramp up to new heights.

In the hunt for new and better battery materials, scientists found an unexpected hero: crab shells.Researchers at the University of Maryland have uncovered a remarkable breakthrough by exploring their use in battery production.

Rock Lobster

Crab shells contain chitosan, a carbohydrate material that is proving useful as a component in battery electrolyte. Credit: John Gibbons

The quest for advanced energy storage materials has been a driving force behind numerous research endeavors worldwide. Traditional lithium-ion batteries have come to dominate in many fields. They power the vast majority of our personal electronic devices, as well as electric vehicles and large grid storage projects. While effective, face limitations in terms of cost, finite resource availability, and safety concerns. As a result, scientists have been exploring alternative battery technologies that offer improved performance, longevity, and scalability.

One such alternative gaining traction is zinc-ion batteries, which have shown promise due to their lower cost and abundance of raw materials. They have comparable performance in some respects, though do have lower power output which makes them suited for less-demanding storage roles. Thus far, their practicality has been hindered by a limited lifespan, hampering their viability. However, the innovative use of material from crab shells could change all that.

The material in question is chitosan—a substance found in abundance within crab and lobster shells. Scientists believe it could be used as a key ingredient in zinc-ion batteries. It’s an unconventional approach that showcases the versatility of natural resources, and could hold the potential to revolutionize the energy storage landscape.

The researchers at the University of Maryland sought to harness the properties of chitosan—a carbohydrate found abundantly in the hard outer skeletons of shellfish—for energy storage applications. By incorporating chitosan into the gel membrane of zinc-ion batteries, they achieved unprecedented results, according to the research paper. The batteries exhibited an impressive year-long lifespan in cycle testing, retaining 70% of their initial capacity—an astonishing improvement compared to existing zinc-ion battery technology.

The chitosan-based electrolyte causes the deposition of neat zinc platelets on the anode of a zinc-ion battery, rather than harmful spiked dendrites. Credit: research paper

Usually, zinc-ion batteries suffer from zinc metal dendrites, which disable the battery after a relatively low number of cycles. This is largely down to the aqueous electrolytes typically used, which allows zinc to form dendritic spikes due to inhomogenous deposition of the metal on the anode over time.

When chitosan is used as part of the electrolyte of the battery, it brings several benefits to the table. It offers strong conductivity and good mechanical strength, and massively improves the cycle stability of zinc-ion batteries. It achieves this by changing the way zinc is deposited on the anode surface. When using the chitosan-based electrolyte, the zinc forms hexagonal platelets that sit neatly in parallel on the anode, instead of forming large dendrites that pierce the battery separator. As a further benefit, the chitosan electrolyte is able to achieve this without unduly compromising the conductivity of the battery.  In testing, the batteries were shown to still be stable after over 400 cycles at a 2C discharge rate, while also demonstrating the ability to charge at up to 20C.

Furthermore, the inclusion of chitosan mitigates safety concerns often associated with lithium-ion batteries. The use of this non-flammable electrolyte reduces the risk of explosions and fire hazards, paving the way for safer and more sustainable energy storage solutions. A further bonus is that zinc-ion batteries could be fabricated in a sustainable and biodegradable manner using chitosan-based electrolyte.

The Glory of Byproducts

Historically, crab shells are discarded from the crab meat production process, and have found limited utility in applications such as fertilizer and animal feed. However, the emergence of chitosan-based batteries presents an exciting opportunity to transform these shells into a valuable resource for renewable energy storage. Mass chitosan production could yet become a serious side-hustle for big players in the seafood industry.

However, while the research has attracted considerable attention, several challenges remain on the path to commercialization. The process of refining and scaling up the production of chitosan-based batteries requires further development, investment, and collaboration with industry partners.

The unexpected alliance between battery research and crab shells exemplifies the remarkable potential of natural materials. By leveraging chitosan from discarded crab shells, scientists have achieved breakthroughs in energy storage that could transform the renewable energy landscape. As the world continues to hunt for new battery solutions, the humble crab could be our latest ally in this area.

32 thoughts on “Crab Shells Massively Improve Zinc-Ion Batteries

    1. You should not listen to MP3 music either, because the earliest psychoacoustic models were created using electrodes wired up to the partially dissected ears of live frogs. Oddly enough the institutions doing the research in the 70’s, 80’s and early 90’s have chosen not to make their detailed papers online. Most of the papers I remember reading at the time were from research done in the UK and Japan.

        1. Psychoacoustics was one of the things that helped shoehorn AAC and mp3.

          They use differing bit sized chunks for different frequency blocks, based on how humans perceive that block.

        2. From Wikipedia “MP3 compression works by reducing (or approximating) the accuracy of certain components of sound that are considered (by psychoacoustic analysis) to be beyond the hearing capabilities of most humans. This method is commonly referred to as perceptual coding or as psychoacoustic modeling. The remaining audio information is then recorded in a space-efficient manner, using MDCT and FFT algorithms.”

          The original experiments as far as I can remember involved playing sounds into frog ears at different frequencies and amplitudes and then analysing the electrical signals after partial processing by some ganglia (name for any neurons outside of brain) inside the ear.

          So you would play a tone at say 500 Hz and a second tone at say 550 Hz simultaneously where one tone was say 50 dB lower in amplitude and see what electrical signals out would changed. And then you would rinse and repeat many many many times at different frequencies and different relative amplitudes. Recording measurements how the outputs from the banks of connected electrodes would change. Eventually this data would form a mathematical model called a “psychoacoustic model” where some data would be discarded based on how much energy was at different frequencies and amplitudes.


          The origin of the original data for the models has been sanitised into nice clean algorithms.

    1. From a parody of the old “Monster Mash” song at :-)

      Out from the crypt Drac’s voice did ring
      Seems he’d discovered some little thing
      He’d picked up a cell, and took a big bite
      And said, “You know, blood’s an electrolyte!”

  1. Scientists have found a material in hotdogs that is essential to all life!
    It’s called water!

    That’s you.
    That’s what you just did.

    Yes. Chitosan has been a hot topic for a few years.
    We have a shit load of it. It would be cool to find some uses for it.
    It is borderline free. That is how much there is.

    But most of it isn’t coming from crabs or lobster.
    It is a waste product of shelling shrimp, and recovered from spoiled stock of krill and other tiny shellfish. Mostly in the Asian market.

    Was there REALLY a need to sensationalize this by talking about crabs?
    Did we really need the crab picture?

    You realize this site caters to nerds who are likely MORE interested in the science stuff than a clickbait story about (insert animal). Right?

        1. self-heating coefficient vs cell temperature for those two are much lower.
          GWL did a nice video “Dangerous vs. Safe batteries, Explosion and fire test!”
          which compares LiPo vs LiFePO4 vs LTO in overcharging and physical damage tests.
          LiPo does huge fire and LFP/LTO emit gasses, which can be secondarily ignited.
          one issue is when Oxygen is generated by the chemistry in overheating condition.
          which varies from chemistry to chemistry

  2. [Pedantic nerd alert]. Chitosan “[…] is made by treating the chitin shells of shrimp and other crustaceans with an alkaline substance, such as sodium hydroxide.” The shells don’t contain chitosan, they contain chitin. And you have to react, extract and purify the chitosan in order for it to be useful.

    1. Sounds a bit fishy. I think we already use a common biological origin polysaccharide in plenty of batteries. Cellulose. Chitin is only the second most abundant ‘natural’ polymer- it doesn’t grow on trees you know.

    1. HOLD UP!

      You mean to tell me that greed and business might lead to battery farms of excess amounts of wildlife to be raised poorly and mistreated just for the sake of another supply to add to the chain?! The nerve.

      *warning: floor wet with sarcasm. step lightly*

  3. “Rock Lobster” was etched on the Amiga 500/A500 mobos. Actually it was B52/Rock Lobster ( song by the B52s )… following Amiga mobos had B52 songs etched on them except the Amiga 1000.

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