Automotive

Envia Systems claims energy density record for lithium-ion batteries

Envia Systems has developed a lithium-ion battery which is claimed to have two to three times the energy density of existing li-ions
Envia Systems has developed a lithium-ion battery which is claimed to have two to three times the energy density of existing li-ions
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Envia's battery could drastically reduce the price of electric vehicles, as the company claims that it should sell for half the price of regular lithium-ion cells
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Envia's battery could drastically reduce the price of electric vehicles, as the company claims that it should sell for half the price of regular lithium-ion cells
Envia Systems has developed a lithium-ion battery which is claimed to have two to three times the energy density of existing li-ions
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Envia Systems has developed a lithium-ion battery which is claimed to have two to three times the energy density of existing li-ions
Close-up images of Envia's HCMR cathode (left) and its silicon-carbon nanocomposite anode
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Close-up images of Envia's HCMR cathode (left) and its silicon-carbon nanocomposite anode

This Monday, California-based Envia Systems made an announcement that could mean big things for the mainstream acceptance of electric vehicles. The company claims to have broken the world record for energy density in a rechargeable lithium-ion cell, with an automotive-grade battery that reportedly has a density of 400 watt-hours/kilogram (Wh/kg). Not only is that figure two to three times higher than what is currently possible with commercially-available cells, but Envia also claims that its battery should cost less than half the price of existing li-ion batteries.

Testing of the battery was performed by the Electrical Power Systems Department at the Naval Surface Warfare Center in Crane, Indiana. The tests were sponsored by ARPA-E (Advanced Research Projects Agency - ENERGY), a division of the U.S. Department of Energy.

Envia's battery could drastically reduce the price of electric vehicles, as the company claims that it should sell for half the price of regular lithium-ion cells
Envia's battery could drastically reduce the price of electric vehicles, as the company claims that it should sell for half the price of regular lithium-ion cells

According to Envia, the battery "demonstrated energy density between 378-418 Wh/kg for rates between C/3 to C/10 for a 45 Amp-hour (C/3) cell." Similar cells, which the company has had cycling in its lab for over 300 cycles, are also slated for further testing.

The secret to the battery's high energy density is said to lie in the company's proprietary cathode, anode, and electrolyte materials.

Close-up images of Envia's HCMR cathode (left) and its silicon-carbon nanocomposite anode
Close-up images of Envia's HCMR cathode (left) and its silicon-carbon nanocomposite anode

The chemistry of the High Capacity Manganese Rich (HCMR) cathode is a fine-tuned version of that of the "layered-layered" cathode, created at Argonne National Laboratory. It consists of nickel, cobalt, manganese and Li2MnO3 (lithium-manganese-oxide). Envia has introduced a patented nanocoating process to that mix, to enhance cycle life and safety. The HCMR is said to have twice the capacity of regular cathodes, and should be available for use in pilot vehicle projects later this year.

A low-cost silicon-carbon nanocomposite acts as the anode. The composition of the Envia-developed electrolyte isn't being revealed, although it is reportedly able to remain stable at higher voltages than currently-used materials.

General Motors, which recently invested US$7 million in Envia, will be performing further tests on the battery. It has also secured the rights to use the HCMR cathode in its electric vehicles.

Source: Envia Systems via IEEE Spectrum

11 comments
livin_the_dream
If I understand the capacity chart well the cell has decreased 34Ah to 26Ah (76%) in about 400 recharge cycles. Surely that is useless, even with triple capacity? Very rough calcs: Assuming triple capacity, then the cell quantities will be reduced to 60% to save weight with ranges of maybe 200 miles. This means it for me personally it would need recharged every 2 days, x 400 = 2.7 years and range will be reduced to 150 miles. this will mean returning to daily charging and more rapid depletion. Won't last many years!
inventor
livin the dream where specifically did you find the information on the end of life for your rough calculations. I see no dropoff curve or statement to suggest it is useless at 400 charges. In fact the curve suggests that tested it to about 450 charges and from the curve, with a steady decrease. If you look at a bout the 150 charge mask it is at 30 at the 400 appears to be at 26. projecting that out it may be about 4-6 times what you projected for end of useful life. Also note it appears for you it may not be a solution but if the ones being sold today are workable for a decent size market doubling the range could open the market up for significantly more people and other modes like motorcycles, bicycles.
Gregg Frank
I agree with inventor on livin_the_dream's calculations. But even if they were on, the decrease in cost of the batteries along with our recycling technology for the lithium-ion (I admit I'm assuming that even though the density of the batter is greater, that current recycling methods will still work equally as well) it's a far superior alternative for people who do shorter trips and want to keep their total carbon footprint as small as possible, then our current petroleum fueled vehicles. I'm very excited about this breakthrough! :)
Slowburn
AGW has been proven to be a fraud, and lithium batteries are more dangerous than gasoline, propane or high presser methane.
Nehemiah Spencer
@slowburn, what do you mean by AGW, and can you provide references? Further, to say lithium batteries are more dangerous than gasoline is a very broad and unsubstantiated statement. There have been no real-life fires associated with electric vehicle crashes, but there are several hundred thousand gas vehicle accident-related fires annually. Google it.
Slowburn
re; Nehemiah E. Spencer Anthropogenic Global Warming Start by looking at the leaked emails. Saying that the trivial number of lithium battery vehicles on the roads today not having had a catastrophic failure yet proves them equally safe to the hundreds of millions of gasoline cars on the road is ludicrous.
Jim Parker
Slowburn, it's intellectually dishonest to take a few snarky emails out of context and then use that as an excuse to ignore the vast amount of evidence indicating that global climate change is very real and doing real damage right now to this planet. You think scientists don't get mad and say stupid things now and then? Get real, and then...get real. Quit letting Murdoch's monkeys pollute your brain with propaganda. You have doubts? Every denier's argument is nailed at skepticalscience.com. Read it and learn something.
Slowburn
re; Jim Parker I did I got tired of the lies. The Climatic Research Unit of University of East Anglia destroyed their raw data (if they ever had any) rather than let anybody else see it. Given that they refused the request to see the data using the English equivalent of the freedom of information act this violated the law, unfortunately the statue of limitations ran out. Remember the infamous hockey stick graph.
Adam Bradley
There's no saving some people.
sutski123
@slowburn AGW maybe, but POLLUTION is definitely made by us. Look at any big city and see what human's are doing to the air!!! AGP should be the focus here not some wishy washy easy to discredit AGW arguement. STOP AGP!!