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More than three decades after its commercial introduction, the lithium-ion (Li-ion) battery remains the electrical energy storage device of choice for applications ranging from consumer electronics and grid storage, to electric vehicles. With such a wide range of applications, researchers are being tasked to come up with even more innovative technologies and chemistries to increase performance and improve the safety of fast charging batteries.
So, while the anode and cathode are key to determining the performance and characteristics of the battery, electrolytes also have a vital role to play as they facilitate the movement of lithium ions between the positive and negative electrodes during charging and discharging cycles.
As a result, the composition of electrolytes has a significant impact on the overall performance and safety of lithium-ion batteries, particularly when it comes to fast charging devices.
Traditionally, electrolytes have consisted of carbonate solvents and lithium salts. However, these conventional electrolytes are not always the best solution for the rapidly evolving chemistries found in nascent fast-charging Li-ion batteries. To fully realize the potential of fast charging, long lasting and safe Li-ion batteries new electrolyte solutions are being studied.
StoreDot’s breakthrough patent for electrolytes, which contain four-carbon chain esters as linear components, offers unprecedented benefits in terms of safety, performance, and charging speed. The patented electrolyte solution is designed to overcome the limitations of conventional electrolytes in applications such as extreme fast charging EV lithium-ion batteries.
United States Patent and Trademark Office: Electrolytes containing a linear solvent with four-carbon chain esters developed for fast charging lithium ion batteries »
The key to StoreDot’s invention lies in the utilization of four-carbon chain esters as a linear component, combined with a cyclic carbonate solvent comprising vinyl carbonate (VC), and at least one lithium salt together with a small amount of additives.
These four-carbon chain esters’ exceptional chemical properties enhance the performance and safety of fast charging Li-ion batteries by enabling the efficient flow of ions while reducing the risk of side reactions, such as the formation of lithium dendrites.
This unique electrolyte solution offers several compelling benefits that address the limitations of conventional electrolytes in fast charging Li-ion batteries:
- Enhanced Safety:
StoreDot's electrolyte solution mitigates safety risks by stabilizing the solid-electrolyte interface (SEI) at the surfaces of the anode material particles. This protective layer prevents the development of hazardous side reactions, such as the formation of dendrites that often result in thermal runaway events.
- Improved Performance:
The four-carbon chain esters facilitate faster ion transport, enabling rapid charging without compromising the cycling lifetime. This breakthrough technology allows for significantly reduced charging times, making it ideal for applications, such as EVs, that require a fast charging-turnaround, to meet customer expectations.
- Polymerization Control:
The addition of specific additives, such as dithioester compounds, serves as polymerization controlling agents in the electrolyte. These compounds regulate the chain length of poly-olefins, which are formed in-situ during cycling. By controlling the level of polymerization, StoreDot's electrolyte solution optimizes battery performance and prevents parasitic reactions that can reduce the efficiency of the battery.
- Oxygen Scavenging:
Some of the electrolyte additives in StoreDot's solution function as oxygen scavengers, removing excess oxygen from the cell. This scavenging action prevents the accumulation of oxygen, which can degrade the battery components and impact overall performance.
- Compatibility with Anode and Cathode Materials:
StoreDot's electrolyte solution is compatible with a wide range of anode and cathode materials. Whether it's silicon (Si), germanium (Ge), tin (Sn), or lithium iron phosphate (LFP), StoreDot's technology can be seamlessly integrated into a wide range of battery architectures.
As the demand for faster and more efficient energy storage solutions continues to grow, StoreDot's innovative electrolyte technology holds the promise of revolutionizing the battery industry. With its enhanced safety features, improved performance, and compatibility with different battery materials, StoreDot's electrolyte solution is set to play a crucial role in the future of energy storage.
By improving safety, performance, and cyclability, StoreDot's breakthrough electrolyte paves the way for the widespread adoption of fast-charging Li-ion batteries, seen as crucial to the acceleration of widespread EV adoption.