Oxis Energy polymer Li-S pouch cell surpasses 450 cycles
31 May 2013
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| Oxis’ standard polymer Li-S pouch cell has surpassed 450 cycles. Click to enlarge. |
Oxis Energy, a UK-based developer of lithium-sulfur batteries, reported via Twitter that one of its standard polymer Li-S pouch cells surpassed 450 cycles this week. Oxis has developed a patented polymer lithium sulfur (Li-S) based battery technology platform using a lithium metal anode, a sulfur-based cathode, and a lithium sulfide electrolyte rendering the Li metal anode safe.
Battery systems using metallic Lithium offer very high specific energy; sulfur represents a natural cathode partner for metallic Li. A lithium-sulfur couple has theoretical specific energy in excess of 2,700Wh/kg. Oxis demonstrated 300 Wh/kg in 2010; the company has a target of 600 Wh/kg in 2016. (Sion Power, supported by an ARPA-E grant, also has a 600 Wh/kg in 2016 target for its Li-S batteries. Earlier post.)
Despite potential advantages of cost and capacity, however, Li-S cells suffer from significant capacity fading during cycling (e.g., earlier post) and have not as yet achieved broad commercialization.
In January 2013, Oxis and Arkema, a global leading chemicals producer, signed a Joint Development Agreement to further improve the performance of the Polymer Lithium Sulfur cells battery. OXIS and Arkema identified several areas where key enhancements could be made, both in terms of both power delivered and reliability of Polymer Lithium Sulfur electro-chemical technology.
Under the agreement, Arkema will provide access to different specialty materials such as carbon nanotubes, electrolyte and advanced technical polymers that could be tested by OXIS for use in developing and extending its technology. The collaboration’s aim is to optimize two aspects: the conductivity increase of the electrolyte that should improve energy density, and reinforcement of mechanical resistance of some components in order to extend the lifetime and safety of the battery.
Also in January, Oxis and Bayer MaterialScience AG signed a two-year Joint Development Agreement on the development of new materials for use in lithium sulfur battery systems.
The company also entered a joint manufacturing agreement with GP Batteries International Limited, Singapore, to accelerate the commercialization of the proprietary lithium sulfur (Li-S) battery systems for use in different energy sectors of the world market.
This could be an important step towards long lasting 600 Wh/Kg batteries for practical next generation extended range BEVs and lighter PHEVs sometime between 2018 and 2020.
Posted by: HarveyD | 31 May 2013 at 11:25 AM
300wh/kg in a 200kg BEV battery would give about 200 miles per charge for a total of 90,000 miles. Not bad depending on the cost. Probably it would give more milage if you're not driving 200 miles every day.
Posted by: Zhukova | 31 May 2013 at 12:47 PM
No ~fade shown. Where's the remaining 1000 cycle part? 2000?
Posted by: kelly | 31 May 2013 at 01:27 PM
The most significant data is that there was shown zero capacity degradation after 450 cycles! This may mean that the pack can be extrapolated to last many thousands cycles? This will be great news for PHEV's, because the battery pack will be lighter and perhaps more compact and may be cheaper than existing chemistries, and will make the PHEV competitive with existing ICEV's in term of weight, handling, and luggage space, as well as overall cost of ownership! This will open the gate for mass acceptance of PHEV's.
Kit P will no longer be able to ridicule the "hauling [heavy] battery around" aspect of PHEV!
Posted by: Roger Pham | 31 May 2013 at 06:14 PM
Sounds great, but we should see both power and energy ratings. The 'pouch' makes it sound flexible, but I doubt it. Lots of theoretical room to grow - at least 4x. Hopefully more to come!!! Good news.
Posted by: william g irwin | 01 June 2013 at 04:23 AM
A "pouch cell" is just a set of materials in a container suitable for lab testing. It's not packaged for any other purpose.
Posted by: Engineer-Poet | 01 June 2013 at 09:42 AM
A Lithium Sulfur battery with very little capacity fade would be a good development.
Posted by: TexasDesert | 01 June 2013 at 02:35 PM
Geez. If they can really hit that 600Wh/kg target, can you imagine an 85kWh Model S with a 142kg battery?!?
Compare that to ~550kg today. that 400kg (880lbs) would make one hell of a big difference in performance for the Model S. It would allow them to cut another couple hundred pounds off the car on top off all that without the need to support so much weight.
Posted by: DaveD | 01 June 2013 at 08:36 PM
It would allow much smaller vehicles to have the same performance and range, since the battery's fraction of the total weight goes down so much.
Posted by: Engineer-Poet | 02 June 2013 at 02:27 PM
Yes, BEVs with 600+ kWh/Kg battery may effectively be lighter than equivalent ICEVS with their heavy engine, multiple essential accessories, heavy drive train and a large gas tank with 18 gallons of gas.
Posters could then tell Kit that he should be tired of moving all his ICEVs heavy dead load around?
Posted by: HarveyD | 03 June 2013 at 10:30 AM
Even if it lasted "only" 500 cycles, at 600Wh/kg you should be able to build a 300 mile range battery into most cars. At 300 miles of range, the battery has a life of 150,000 miles.
Posted by: Anthony F | 03 June 2013 at 02:15 PM
What will be the total effect on the economy when BEVs are equipped with 20+ year batteries, drive trains, ancillaries and can go up to 10 Km on a single kWh?
That's what happened with good quality Desktops, Laptops and large LCD/LED TVs? Many of them are still going strong after 10+ years....sales of new replacement units are going down?
Will the Big-3 manage to build BEVs with the same high degree of obsolescent they did for ICEVs for decades?
Posted by: HarveyD | 14 June 2013 at 04:59 PM