International researchers have recently uncovered the fundamental mechanisms behind the degradation of lithium-ion batteries, a finding that could lead to breakthroughs in battery design, improve performance, and extend the lifespan of electric vehicles (EVs). This research not only opens up prospects for the electric vehicle industry but may also promote solutions for clean energy storage.
Lithium-ion batteries are among the most widely used energy storage technologies today, but over time, their energy storage capacity diminishes. This is why older electronic devices often deplete power more quickly. However, the actual causes of this phenomenon have not yet been fully understood.
A team of researchers led by experts from the University of Colorado Boulder has published new findings on the self-discharge mechanisms of lithium-ion batteries. By utilizing powerful X-ray machines at the Argonne National Laboratory (USA), they identified that hydrogen molecules in the battery’s electrolyte can interfere with the movement of lithium ions. This interference reduces capacity and weakens battery performance over time.
Lithium-ion batteries are a great technology, but nothing is perfect. Their degradation over time is a natural phenomenon influenced by many factors.
This discovery, published in the journal Science, promises significant improvements in the lifespan and performance of lithium-ion batteries. Michael Toney, the lead author of the study, noted: “Understanding the molecular-level mechanisms behind the degradation of lithium-ion batteries will help drive the development of more sustainable batteries. This is crucial for reducing reliance on fossil fuels and transitioning to renewable energy.”
Many automakers are shifting towards electric vehicles, but they face challenges such as short battery life and limited range. A typical electric car in the U.S. market can currently travel about 250 miles on a single charge, while gasoline vehicles can travel much further. Toney believes this research could help address these issues, while also reducing production costs and enhancing battery performance.
During charging and discharging, lithium ions move back and forth between the positive and negative electrodes. This process creates imperfect chemical reactions, leading to the formation of coatings on the electrode surfaces. These coatings hinder the movement of lithium ions, reducing the battery’s capacity and performance. Other side reactions can also occur, causing degradation of the electrolyte and other battery components.
One of the major challenges in battery manufacturing is the use of cobalt, a rare and expensive element. The primary supply of cobalt comes from the Democratic Republic of the Congo, where mining poses serious health and environmental issues. As a result, scientists have sought to replace cobalt with other elements such as nickel and magnesium. However, these types of batteries tend to self-discharge more quickly, leading to energy depletion and reduced battery lifespan.
Toney and his colleagues’ recent study has demonstrated that self-discharge is not only caused by lithium ions failing to return to the positive electrode during charging but also due to hydrogen molecules in the electrolyte occupying space where lithium ions would be at the negative electrode. This leads to a decrease in battery capacity and directly impacts the performance of battery-powered devices, including electric vehicles.
High temperatures accelerate the rate of chemical reactions inside the battery, hastening the degradation process. Conversely, extremely low temperatures can also adversely affect battery performance.
Every charge and discharge cycle causes some damage to the battery. The more charge-discharge cycles, the faster the battery degrades. Deep discharging (nearly empty) also accelerates degradation. Rapid charging can generate significant heat, harming the battery. Improper storage, such as keeping the battery in a humid, too hot, or too cold environment, also contributes to reducing battery lifespan.
Gaining a better understanding of these mechanisms will help engineers develop measures to prevent battery degradation. One potential solution is to coat the negative electrode with special materials to prevent the interference of hydrogen molecules, or to replace the electrolyte with a different type. The research team is also exploring ways to optimize battery components to extend lifespan and enhance performance, enabling electric vehicles to have longer ranges and lower production costs.
The degradation of lithium-ion batteries is inevitable, but we can extend their lifespan through proper use and storage. Understanding the causes and factors affecting degradation will help you take effective preventive measures.
This discovery not only holds great potential for the electric vehicle industry but also contributes to advancing renewable energy storage solutions, reducing dependence on fossil fuels. With these improvements, consumers may one day own electric vehicles with longer battery lifespans, greater ranges, and contribute to environmental protection goals.
