ORNL team develops metal-free current collector
22 January 2024
Researchers at the Department of Energy’s Oak Ridge National Laboratory have developed a lighter, metal-free current collector made of a polymer-based composite with carbon fibers. The aligned fibers work together with a thin film of carbon nanotubes to enhance directional and uniform current flow.
Lab tests conducted at medium-fast battery charging rates showed the novel current collector performed as well as or better than the standard copper foil. ORNL’s carbon polymer material is less prone to corrosion and can stretch more easily for roll-to-roll manufacturing of electrodes. A paper on their work is published in the Journal of Energy Storage.
The requirement for high energy density batteries is driving the development of high-capacity electrode materials while reducing the amount of inactive battery components such as separators, binders, and current collectors.
Though current collectors are an inactive component, they are still required for successful working of a battery cell. Conventional current collectors include aluminum foil for cathode and copper foil for anode. Copper foil is quite heavy (8.7 mg/cm2) for 10 μm thickness. Therefore, there is a need for a lightweight current collector for anode applications.
—Sharma et al.
The ORNL researchers developed a metal-free current collector comprising aligned carbon fiber (CFs) layer filled with carbon nanotubes (CNTs) mixed in polymer (P) as a current collector for anodes.
Anodes coated on the CF-CNT-P showed lower charge transfer resistance and improved rate capability compared with the anodes fabricated on conventional copper foil-based current collectors.
The CF-CNT-P are lighter (≈1.5 mg/cm2) than the commonly used copper foil (8.7 mg/cm2), which will increase the gravimetric energy density.
We are reducing 80% to 90% of the weight of the current collector. This will help a lot in increasing the energy density of battery packs.
—Jaswinder Sharma, lead and co-corresponding author
The researchers have file a patent application on the development. (J. Li, J. Sharma, A metalless current collector, Patent Application # 63/455,587).
Resources
Jaswinder Sharma, Runming Tao, Georgios Polizos, Nihal Kanbargi, Benjamin LaRiviere, Jianlin Li (2024) “A lightweight and metal-free current collector for battery anode applications,” Journal of Energy Storage, Volume 79 doi: 10.1016/j.est.2023.110161
It appears that the vision of Hideaki Horie of an ALL POLYMER BATTERY may be the next generation of Lithium batteries. No Cobalt, Nickel, Copper, or any metal other than Lithium (possibly even a blend of Sodium and Lithium).
A recent GCC post discussed a high energy Quinone Cathode developed by MIT.
https://www.greencarcongress.com/2024/01/20240119-taq.html
CATL has developed a Semi-Solid Condensed battery with a Biometic electrolyte.
Toyota is working with Idemitsu to produce Sulfide solid electrolytes.
APB (Hideaki Horie’s company) is working with Saudi Aramco.
Harvard researcher Xin Li has shown that Lithium Metal batteries can have a long life if they use a solid electrolyte.
References:
https://seas.harvard.edu/news/2024/01/solid-state-battery-design-charges-minutes-lasts-thousands-cycles
https://www.japantimes.co.jp/news/2023/03/28/business/apb-saudi-aramco-partnership/
https://global.toyota/en/newsroom/corporate/39865919.html
Posted by: Gryf | 22 January 2024 at 10:00 AM
Thanks Gryf.
For those of us who were going: 'Who he?' from Gryf's reference to Hideaki Horie as I did:
https://asia.nikkei.com/Business/Electronics/Former-Nissan-EV-developer-to-launch-plastic-battery-this-year
Most of the rest is way above my pay grade.
In the 15 years or so I have been following batteries, it is one of the few things I agree with Musk about, in that battery companies bring a whole other level of bull to the table.
We are still nowhere near being able to produce a small car at the entry level, where most of the world's future motorists will be, at an ex-subsidy price comparable to ICE.
In the effort to do so, with increased energy density at good cost disappointing, they are building the batteries into the structure, and partly due to that the average lifespan of cars is now decreasing, as any damage to to any oldish, and some newish, cars, results in their being scrapped as not worth repair.
That is pretty much the opposite of ecological.
None of this should be taken as any sort of rejection of battery electric cars, although in my view it is premature to dismiss hybrids etc with smaller batteries, and I have no serious doubt that sooner or later we will get there.
The horizon has been ever receding for many years though, with mostly bull filling the gaps, although of course there has been genuine progress.
Posted by: Davemart | 22 January 2024 at 11:57 AM
Copper foil is used on the anode in lithium ion batteries, with sodium ion batteries they can use aluminum on both the Anode and cathode, that reduces cost.
Posted by: SJC | 22 January 2024 at 05:09 PM