Dave Rittenhouse | Magnera: What happens to a battery separator at 200°C, and can it be engineered to shut down safely?
00:08:46.275 - 00:09:47.725
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Summary of the clip:
What happens to a battery separator at 200°C, and can it be engineered to shut down safely?
Thermal stability is a critical safety parameter for any battery component, especially the separator which prevents internal short circuits. This clip provides a dramatic visual demonstration of this property, comparing Magnera's high-temperature separator to a conventional stretched film after both were exposed to 200°C for one hour. While the conventional separator completely melts into two small drops, the OmniSep material maintains its form and structural integrity, showcasing a vastly superior safety factor under extreme heat.
Beyond simply surviving high temperatures, an advanced separator can be engineered with active safety features. Magnera has developed a version of their separator with a "shutdown" capability. This feature is designed to activate at a specific trigger temperature, in this case around 120°C, to proactively prevent a thermal runaway event before it can escalate.
The mechanism for this safety feature is a rapid increase in the separator's internal resistance. A graph shows that upon reaching the 120°C trigger point, the material's ionic resistance increases by approximately 15 times. This sudden spike in resistance effectively chokes off the flow of ions, shutting down the cell's electrochemical reaction and providing a crucial safety stop. The speaker also notes the availability of bimodal shutdown separators that offer a broader temperature response range.
In this short video, you can learn:
* A visual demonstration of superior thermal stability at 200°C compared to conventional separators.
* How an engineered shutdown feature can be integrated into the separator material.
* The mechanism of a shutdown separator, which rapidly increases ionic resistance at a trigger temperature to safely stop cell operation.
📋 **Clip Abstract** Safety is paramount in battery design. This clip showcases the exceptional high-temperature stability of Magnera's separator and explains their engineered shutdown capability, a critical safety feature that can prevent thermal runaway.
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#ShutdownSeparator, #ThermalStability, #IonicResistanceIncrease, #OmniSep, #LithiumIonBatteries, #BatterySafety
This is a highlight of the presentation:
Unique Separator made using Fiber Formation
More Highlights from the same talk.
00:03:01.355 - 00:05:12.555
How can a separator's microscopic structure unlock better battery performance?
How can a separator's microscopic structure unlock better battery performance?
Conventional lithium-ion battery separators are typically made using a "dry process." This involves extruding a polymer like polypropylene and then stretching it in one direction. This stretching process pulls apart the crystalline and amorphous regions of the polymer, creating a structure of ladder-like crystalline "rungs" connected by incredibly fine, nano-scale fibrils. While this creates pores for ions to pass through, the enormous surface area of these tiny tendrils creates significant resistance, or tortuosity, which can impede ion flow and limit battery performance.
In stark contrast, Magnera's OmniSep separator is built from a nonwoven, fiber-based material. Instead of stretching a film, their process involves depositing what are described as "infinitely long fibers" and compressing them into a sheet. The resulting structure is fundamentally different, creating a more open and interconnected network of pores, rather than the constrained, fibrillated structure of a stretched film. This architecture is key to its performance advantages.
The direct consequence of this fiber-based structure is a separator with inherently higher porosity and lower resistance to ionic flow. This translates into tangible benefits like faster electrolyte wet-out and wicking, which are critical for cell manufacturing and performance. By designing the separator's microstructure from the fiber level up, it's possible to achieve superior ionic conductivity, which is essential for high-rate charging and discharging.
In this short video, you can learn:
* The structural difference between conventional "dry process" separators and nonwoven fiber-based separators.
* How the stretching process creates nano-scale fibrils that can impede ion flow.
* Why a fiber-based architecture leads to a more open, interconnected pore structure for better performance.
📋 **Clip Abstract** Discover the fundamental structural differences between traditional stretched-film separators and Magnera's innovative fiber-based nonwoven material. This clip explains how the manufacturing process dictates the separator's microscopic architecture, directly impacting battery performance.
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#SeparatorMicrostructure, #NonwovenSeparators, #PoreArchitecture, #IonicConductivity, #SolidStateBatteries, #SodiumIonBatteries
00:07:18.665 - 00:08:45.405
Can a simple separator swap extend your battery's cycle life and boost its power?
Can a simple separator swap extend your battery's cycle life and boost its power?
When evaluating a new battery component, long-term cycling data is the ultimate test of durability and performance. In this clip, Dave Rittenhouse presents cycling results from an NMC811 cell, directly comparing the OmniSep separator to a standard stretched film. The data clearly shows superior capacity retention for OmniSep out to 700 cycles, with extrapolations projecting a cycle life of 2,200 to 2,700 cycles, significantly outperforming the incumbent technology.
Beyond longevity, the ability to charge and discharge quickly is critical for many applications. The presentation details a rate capability test using a protocol that steps up the charge rate from C/3 to 3C. Throughout this test, the cells built with the OmniSep separator consistently demonstrate slightly better capacity retention than the control cells, proving the material's ability to facilitate rapid ion transport even under demanding charge conditions.
The most extreme test of power delivery is pulse performance. The clip showcases data from a 30-second pulse discharge test, pushing the cells to an incredible 16C rate. Even at these very high power outputs, the OmniSep separator continues to enable superior performance compared to the stretched film. This highlights its low internal resistance and suitability for high-power applications like drones and directed energy weapons.
In this short video, you can learn:
* Long-term cycling data showing superior capacity retention for OmniSep compared to stretched films.
* Rate capability results demonstrating excellent performance at charge rates up to 3C.
* High-power pulse discharge performance, maintaining superiority at rates as high as 16C.
📋 **Clip Abstract** This clip presents compelling electrochemical data comparing Magnera's OmniSep to traditional stretched-film separators. See the head-to-head results for long-term cycle life and high-rate capability, demonstrating significant performance improvements.
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#OmniSepSeparator, #NMC811, #BatterySeparator, #CycleLifeExtension, #HighPowerBatteries, #AerospaceDefense