Researchers have discovered that the formation of “oxygen holes” considerably undermines the integrity of Ni-rich cathode materials in lithium-ion batteries. By employing sophisticated computational methods, they have pinpointed a process for the escape of oxygen and suggested the use of dopants to improve the battery’s resilience and lifespan.
A significant advancement has been made in comprehending and resolving the difficulties related to Ni-rich cathode materials in lithium-ion batteries. Although these materials have the potential for high voltages and capacities, their practical application has been restricted by structural inadequacies and the loss of oxygen.
The investigation disclosed that the occurrence of “oxygen holes”—a condition where an oxygen ion sheds an electron—has a pivotal role in the deterioration of LiNiO2 cathodes. This leads to an accelerated release of oxygen, which further compounds the degradation of the cathode substance.
Utilizing a series of cutting-edge computational methodologies on regional supercomputers in the UK, the research team scrutinized the conduct of LiNiO2 cathodes during charging cycles. They established that the material’s oxygen undergoes transformations, whereas the nickel’s charge remains largely constant.
Co-author Prof. Andrew J. Morris of the University of Birmingham stated, “We ascertained that the nickel ions maintain a charge close to +2, irrespective of their charged or discharged state. Concurrently, the oxygen charge oscillates between -1.5 and roughly -1. Contrary to conventional models, which postulate a steady -2 charge for oxygen throughout the charging process, we’ve determined that oxygen is unstable, revealing a route for its departure from the Ni-rich cathode.”
The research team validated their computational outcomes by juxtaposing them with empirical data, concluding that their findings closely match observed phenomena. They outlined a mechanism by which oxygen departs from the material. This involves the fusion of oxygen radicals to produce a peroxide ion, which subsequently decomposes into oxygen gas, creating vacancies in the material. This event discharges energy and generates singlet oxygen, an extremely reactive form of oxygen.
“By introducing dopants that dampen oxygen redox activity, while facilitating transition-metal redox, particularly at the surface, we may mitigate the formation of reactive singlet oxygen. This holds the promise of enhancing the stability and longevity of these lithium-ion batteries, thereby facilitating more efficient and dependable energy storage solutions,” commented first author Dr. Annalena Genreith-Schriever of the University of Cambridge.
Despite their high energy density and rechargeable nature, lithium-ion batteries have been hampered by issues related to the stability of their cathode materials, affecting their overall efficacy and lifespan.
Reference: “Oxygen Hole Formation Governs Stability in LiNiO2 Cathodes” by Annalena R. Genreith-Schriever, Hrishit Banerjee, Ashok S. Menon, Euan N. Bassey, Louis F.J. Piper, Clare P. Grey, and Andrew J. Morris, published on 19 July 2023 in Joule.
DOI: 10.1016/j.joule.2023.06.017
Table of Contents
Frequently Asked Questions (FAQs) about lithium-ion batteries
What is the main focus of this research?
The main focus of this research is to understand the degradation mechanisms in Ni-rich cathode materials used in lithium-ion batteries. Researchers identified “oxygen holes” as a significant factor leading to the degradation of these materials.
What are “oxygen holes” and why are they important?
“Oxygen holes” refer to the condition where an oxygen ion loses an electron. This plays a pivotal role in the deterioration of LiNiO2 cathodes and leads to an accelerated release of oxygen, which further degrades the cathode material.
How did the researchers study the behavior of LiNiO2 cathodes?
The researchers utilized a range of cutting-edge computational techniques and conducted their studies on regional supercomputers in the UK. They analyzed the behavior of LiNiO2 cathodes during the charging cycles to understand changes in oxygen and nickel ions.
What were the key findings about the charge of nickel and oxygen ions?
Contrary to conventional models that assume a stable -2 charge for oxygen throughout the charging cycle, researchers found that the charge of oxygen varies between -1.5 and roughly -1. Meanwhile, the charge of the nickel ions remained relatively constant around +2.
What solutions did the researchers propose to enhance battery stability?
The researchers proposed the use of dopants that can reduce the oxygen redox activity while facilitating transition-metal redox. This approach aims to mitigate the generation of reactive singlet oxygen, thereby enhancing the stability and longevity of the batteries.
What is the potential impact of this research on energy storage systems?
The research holds the promise of substantially improving the stability and lifespan of lithium-ion batteries. By addressing the challenges associated with Ni-rich cathode materials, the findings could lead to more efficient and reliable energy storage solutions.
Who are the principal authors and where was the research published?
The principal authors include Dr. Annalena Genreith-Schriever from the University of Cambridge and Prof. Andrew J. Morris from the University of Birmingham. The research was published on 19 July 2023 in the journal Joule.
Is the research validated by experimental data?
Yes, the computational outcomes were compared with empirical data, and the findings were found to align closely with what was observed in the experiments.
More about lithium-ion batteries
- Journal Article in Joule
- University of Cambridge Research News
- University of Birmingham Research Portal
- Overview of Lithium-ion Batteries
- Advanced Computational Methods in Battery Research
- Energy Storage Systems
- Ni-rich Cathodes in Lithium-ion Batteries
10 comments
Man, the stuff they can do with computational methods these days. Impressive to say the least.
So they used supercomputers to find this out? Tech is going places man, going places.
hold on, does this mean my phone battery won’t die on me every 6 months? Sign me up.
Wow, this is a game changer for sure! Who knew “oxygen holes” were a thing? Can’t wait to see where this research leads.
finally some good news! can’t wait for longer-lasting batteries. Hope this isn’t just another hype.
I’m not a scientist but this seems huge. Better batteries are a need of the hour. Hope this gets to the market soon.
When can we actually see this tech in our daily lives? Seems like it could be a real lifesaver.
Always knew there was more to learn about batteries. This research just proves how much we still don’t know.
so we’ve been getting it wrong all these years? oxygen holes, huh. Interesting stuff.
Absolutely mind-blowing! I mean, this could literally extend the life of our batteries. Big ups to the research team.