A mineral made in a Kamchatka volcano may hold the answer to cheaper batteries, find scientists.
- Russian scientists discover a new mineral in the volcanic area of Kamchatka in the country's far east.
- The mineral dubbed "petrovite" can be utilized to power sodium-ion batteries.
- Batteries based on salt would be cheaper to produce than lithium-ion batteries.
Excited Russian scientists at the edge of the volcanic area in Kamchatka where the mineral was found.
Credit: St. Petersburg University / Filatov
Crystal structure displaying sodium migration pathways.
Credit: Filatov et al., Mineralogical Magazine, 2020
Although everyone knows that coal-based energy is a thing of the past, declarations about nuclear power plants somehow do not want to enter into force.
No other power-generating device raises as much concern as the nuclear reactor. Because of this, until recently the future of the entire energy sector has been determined by its past.
- The International Energy Agency is an intergovernmental organization that advises member nations on issues related to energy and the environment.
- In its annual report, the IEA reported that the cost of solar is dropping more rapidly than previously thought, providing some parts of the world with historically cheap electricity.
- The IEA predicted that, over the next decade, renewables will meet 80 percent of global electricity demand growth, while the demand for oil will peak.
While it's always been a boon to Popeye's "muskles," it looks like spinach may also have a role to play in clean future batteries.
- Scientists are seeking sustainable, clean chemicals for use in future fuel cell and metal-air batteries.
- Platinum is the current go-to substance for battery cathode catalysts, but it poses a number of problems, including high cost and instability.
- Chemists at American University have developed a new high-performance catalyst from simple spinach, although its preparation as a catalyst is anything but simple.
Cathodes and anodes, oh my<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2OTU5MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNDQ0NjA0OH0.Fe2eDSkzfzSBG3bGwDsEdrxOy14JYGuhJGjm9shhtkg/img.jpg?width=980" id="5e913" class="rm-shortcode" data-rm-shortcode-id="22095dc5998edbe5c1e27ec10b5a4cc9" data-rm-shortcode-name="rebelmouse-image" />
Flow of energy when battery is in use, discharging
Credit: VectorMine/Shutterstock/Big Think<p>Electrons travel within a battery from one electrode, called the anode, through the battery's electrolyte — either a powder or liquid barrier — to another electrode, called the cathode. The anode releases these electrons through a chemical process called oxidation, while the cathode accepts them through another, an oxygen reduction reaction. Together, this exchange is called a "<a href="https://en.wikipedia.org/wiki/Redox" target="_blank">redox</a>."</p><p>The electrons' return trip back to the anode, however, requires a "load" provided by an external device, which is fine, since that device — a flashlight, a phone, or a car, for example — operates on the energy produced by the battery's electrons passing through.</p><p>The electrons travel out from the cathode's positive terminal to the device then return to the battery's negative anode terminal. In this way the energy travels <a href="https://www.explainthatstuff.com/batteries.html#parts" target="_blank">round and round</a> the battery-device circuit. (When charging a battery, electrons go in the opposite direction connected to a charger.)</p><p>The new study is concerned with the <a href="https://en.wikipedia.org/wiki/Catalysis" target="_blank" rel="noopener noreferrer">catalyst</a> that produces the cathode's oxygen reduction reaction.</p>
Replacing a problematic, pricey catalyst<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2OTU5Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMjYyNDI1Nn0.pI9itmS82CPFV4nUOAURwP9amjNi6HpPpU2biikLxYs/img.jpg?width=980" id="9685a" class="rm-shortcode" data-rm-shortcode-id="3a29c292ad8026d129250d041f1fac9e" data-rm-shortcode-name="rebelmouse-image" alt="platinum bricks" />
Credit: AlexLMX/Shutterstock<p><a href="https://en.wikipedia.org/wiki/Fuel_cell" target="_blank" rel="noopener noreferrer">Fuel cell batteries</a> and <a href="https://en.wikipedia.org/wiki/Metal%E2%80%93air_electrochemical_cell" target="_blank">metal-air batteries</a> use the surrounding air outside the battery as their cathode. It's clean, free, plentiful, and it works, as long as there's a catalyst that can adequately prompt the requisite oxygen reduction reaction.</p><p>The most commonly used catalysts for such batteries have been based on platinum. There are problems with these, though. Of course, platinum is expensive. Also, as the study notes, "the lack of long-term stability and the vulnerability to surface poisoning by various chemicals such as methanol and carbon monoxide, call for the development of non-Pt group metal (NPGM) catalysts."</p><p>Researchers have therefore been exploring non-toxic, carbon-based catalyst alternatives since they may be more stable and exhibit resistance to surface poisoning. And because carbon is everywhere, they'd be inexpensive to produce. However, some of the materials being investigated don't do the job as well as platinum-based catalysts. The chemical reaction they produce is slow, posing a speed bottleneck to the flow of electrons.</p>
Enter spinach<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2OTYwMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjIxNzI1MX0.Ru_hwAVllm7R2mCfu0X94MdVXpCYbZz3VjcfvsRMaTo/img.jpg?width=980" id="6321d" class="rm-shortcode" data-rm-shortcode-id="f8285054c63c2fc02bef8fba3b29a7cf" data-rm-shortcode-name="rebelmouse-image" />
Credit: Liu, et al./ACS Omega 2020, 5, 38, 24367-24378<p><span style="background-color: initial;"><a href="https://www.american.edu/cas/faculty/szou.cfm" target="_blank">Shouzhong Zou</a></span>, of American University's <a href="https://www.american.edu/cas/chemistry/" target="_blank">Department of Chemistry</a>, is the paper's senior author. The lead author is Xiaojun Liu, with Wenyue Li as co-author. Professor Zou reports:</p><p style="margin-left: 20px;">"The method we tested can produce highly active, carbon-based catalysts from spinach, which is a renewable biomass. In fact, we believe it outperforms commercial platinum catalysts in both activity and stability. The catalysts are potentially applicable in hydrogen fuel cells and metal-air batteries."</p><p>While other catalyst research has involved plants such as rice and cattails, Zou believes spinach has a few things that make it a superior candidate as a catalyst material. For one thing, it's rich in iron and nitrogen, both essential catalyst ingredients. In addition, it's easy and inexpensive to grow, and it's abundant.</p><p>Zou and his students developed spinach-based carbon nanosheets a thousand times thinner than a human hair. The process is complex, a combination of basic and advanced techniques.</p><p>To begin, the researchers washed, juiced, and freeze-dried the vegetable before grinding it by hand into a fine powder using a mortar and pestle. Next, the spinach powder was dissolved and mixed with <a href="https://en.wikipedia.org/wiki/Melamine" target="_blank">melamine</a>, sodium chloride, and potassium chloride in water and cooked together at 120°C. This mixture was then rapid-cooled in liquid nitrogen and freeze-dried. Then it was <a href="https://en.wikipedia.org/wiki/Pyrolysis" target="_blank">pyrolized</a> twice.</p><p>It may well have been worth the effort. Measurements of the resulting nanosheet indicated that it can out-perform platinum as a catalyst in both speed and stability. Of course, that's on top of being made from such an unassuming, inexpensive, and widely available plant.</p><p>"This work," says Zou, "suggests that sustainable catalysts can be made for an oxygen reduction reaction from natural resources." The next step for Zou and his students is to try out their spinach catalyst in prototype fuel cells to assess its performance in action. They're also looking into the use of other plant materials for catalysts.</p><p>Finally, Zou understandably hopes to develop a simple, less energy-intensive way to make their catalyst nanosheets.</p>
Utilizing nuclear waste converted to diamonds, the company's batteries will reportedly last thousands of years in some cases.
- Nuclear reactor parts converted to radioactive carbon-14 diamonds produce energy.
- To keep them safe, the carbon-14 diamonds are encased in a second protective diamond layer.
- The company predicts batteries for personal devices could last about nine years.
Waste not<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU5NDQyMS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTIyNTQxOX0.LnHH-Uj9up_14gGLMii9OpWUj3qZ4kQ3aJ9vr3YNPBQ/img.jpg?width=980" id="db1dc" class="rm-shortcode" data-rm-shortcode-id="4d54eef4ec5902b331313218f4413738" data-rm-shortcode-name="rebelmouse-image" alt="NBD battery" />
NDB's battery as it might look as a circuit-board component
Image source: NDB<p>The nuclear waste from which NDB plans to make it batteries are reactor parts that have become radioactive due to exposure to nuclear-plant fuel rods. While not considered high-grade nuclear waste—that would be spent fuel—it's still very toxic, and there's a lot of it in a nuclear generator. According to the <a href="https://inis.iaea.org/collection/NCLCollectionStore/_Public/32/039/32039321.pdf" target="_blank">International Atomic Energy Agency</a>, the "core of a typical graphite moderated reactor may contain 2000 tonnes of graphite." (A tonne is one metric ton, or about 2,205 lbs.)</p><p>The graphite contains the carbon-14 radioisotope, the same radioisotope used by archaeologists for carbon dating. It has a <a href="https://www.radioactivity.eu.com/site/pages/RadioCarbon.htm" target="_blank">half-life of 5,730 years</a>, eventually transmuting into <a href="https://www.sciencemag.org/news/2008/01/solving-carbon-14-mystery" target="_blank" rel="noopener noreferrer">nitrogen 14</a>, an anti-neutrino, and a beta decay electron, whose charge piqued NDB's interest as a potential means of producing electricity.</p><p>NDB purifies the graphite and then turns it into tiny diamonds. Building on existing technology, the company says they've designed their little carbon-14 diamonds to produce a significant amount of power. The diamonds also act as a semiconductor for collecting energy, and as a heat sink that disperses it. They're still radioactive, though, so NDB encases the tiny nuclear power plants within other inexpensive, non-radioactive carbon-12 diamonds. These glittery lab-made shells serve as, well, diamond-hard protection at the same time as they contain the carbon-14 diamonds' radiation.</p><p>NDA plans to build batteries in a range of <a href="https://en.wikipedia.org/wiki/List_of_battery_sizes#Lithium-ion_batteries_(rechargeable)" target="_blank">standard</a>—AA, AAA, 18650, and 2170—and custom sizes containing several stacked diamond layers together with a small circuit board and a supercapacitor for collecting, storing, and discharging energy. The end result is a battery, the company says, that will last a <em>very</em> long time.</p><p>NDB predicts that if a battery is used in a low-power context, say, as a satellite sensor, it could last 28,000 years. As a vehicle battery, they anticipate a useful life of 90 years, much longer than any single vehicle will last—the company anticipates that one battery could conceivably provide power for one set of wheels after another. For consumer electronics such as phones and tablets, the company expects about nine years of use for a battery.</p><p>The company's prospective investor video explains their process in greater detail.</p>