NMC (Nickel-Manganse-Cobalt) Performance
The future of clean energy electric vehicles relies on the continued development of new, high energy density NMC Li-ion battery cells. These next generation cells will push charge voltages and application requirements to new heights, requiring advancements in all aspects of the battery design system, including but not limited to the electrolyte. Current Li-ion electrolytes are not well equipped to support these new demands. This is where Silatronix® OS3® material can deliver a much-needed boost in overall electrolyte performance.
As outlined below, Silatronix® OS3® has the capability of delivering an improved Li-ion electrolyte for NMC systems, including those that leverage state-of-the-art silicon anode technology. By stabilizing the decomposition of LiPF6 salt in solution, OS3® improves the overall performance of the battery electrolyte. This results in improved high-temperature performance, reduced cell swelling, longer life, and improved safety.
To demonstrate the fundamental mechanism of OS3® material at work, we added various amounts of OS3® material to an EC/DEC carbonate electrolyte solution in sealed, PTFE lined NMR tubes and stored them at 100°C. We performed NMR analysis at regular intervals to observe the decomposition of each solution. After only 18 days, the non-OS3® electrolytes have decomposed rapidly, showing the dark black color. The OS3® enabled solutions however, have been completely stabilized and remain so for over 2 years.
The graph below illustrates what is happening in the above electrolyte samples. Note that HF generation in ppm rapidly rises in non-OS3® solutions (red), while in all OS3 containing solutions, HF generation is completely controlled over time.
Demonstrating performance improvements and fundamental mechanism in the lab is one thing. Demonstrating these benefits in an actual Li-ion battery system is another. To show OS3® at work, the cell level test data shown below illustrates how OS3® electrolyte provides significant cell stabilization through a reduction in swelling via gas generation at high temperature. This case shows a 4.2V NMC multi-layer pouch cell utilizing a proprietary silicon-anode material. The OS3® enabled cells exhibit about half the amount of swelling after 10 weeks of high temperature storage vs the control cells. This reduction in swelling translates to a significant improvement in battery cell life as well as substantial improvements to the mechanical integrity of the battery system in application.
