In energy storage, fantastic claims of game-changing technologies launch, peak and fall rapidly – only rarely does an actual product result. In a press release, ERRA Incorporated of San Antonio, Tex., announced their acquisition of a set of rights and patents for a “breakthrough battery technology” to be marketed as the YESS (Your Energy Storage Solution) Battery from ERRA, Inc. The press release made no mention of the battery’s chemistry, only that it was “Simply the most cost effective energy storage battery module on the planet!” If nothing else, we were curious.
With a little digging, we discovered that ERRA had bought the rights to some important innovations in nickel-hydrogen (Ni-H2) batteries. Ni-H2 is, as the press release indicated, is the same battery tech that has been powering satellites for the last 30 years or so. Not remembering when Sputnik was launched, it can only say that the batteries have been working continuously. NI-H2 can withstand upwards of 20,000 charge-discharge cycles, can be 100 percent discharged, recharged and then used as if nothing happened and still have a zero self discharge rate. The reason they haven’t been used in cars before? Energy per kilogram, the Hindenburg and weight.
Now, ERRA claims to have resolved the last two issues. The energy density per kilogram is still hugely important though, so we’ll talk about that first. Now, a traditional NiH2 cell has anywhere from half to three quarters the energy density of lithium ion cells. Put in a Chevrolet Volt, for instance, this means that instead of 40 miles on Li-Ion, we are getting 20 or 30 miles on NiH2. Even the most urbane of commuters isn’t going to dig it – let alone risk explosions. It just doesn’t have the energy density to get you far enough to sell the things. Two ways to fix this: different chemistry (lithium ion) or reduced weight.
Tradtional NiH2 cells require a substantial pressure vessel to contain the hydrogen gas. The things were great for use in space where a satellite would sit in geosynchronous orbit for a few decades and then become a shooting star, but in automotive applications, the power to weight ratio just wasn’t there due to the cumbersome hydrogen storage vessel.
Of course, there was the risk of Hindenburg-like explosions on the street as well. According to ERRA’s CEO James Hogarth, the hydrogen has been removed from the battery itself in the company’s technology and stored in a solid state. This meant the pressure vessel could be lightened considerably — and that being stored with a negative pressure, any hydrogen leaks would be very slow and burn like a candle instead of a bomb. One hopes that this is accurate. Assuming the safety aspect is taken care of and that effective weight reductions have taken place, what does this mean?
Well, for one, a 40-year old chemistry might have just gotten a new lease on life. If the batteries are substantially lighter as ERRA tells us, then the power to weight ratio is going to be improved dramatically. Coupled with other improvements, ERRA doesn’t want released publicly, we expect substantial improvements in their kilowatt-hour-per-kilogram figures. Without solid numbers from ERRA’s engineering department, we can only guess.
Still, any car battery that can withstand 20,000 charge cyles, be used 100 percent and not damaged, crashed into a brick wall and rendered inert without any real danger, topped off and remain 100 percent three years later is going to be a winner. If ERRA has refined NiH2 to be competitive with Li-Ion’s charge density, while maintaining the robustness of the chemistry and building some safety into it, expect to be hearing about them. A lot.
ERRA has found a manufacturer and expects to be ready for production in six to nine months. It has identified two production lines requiring only a few modifications to start churning out NiH2 cells. They expect the cells to be used everywhere from AAA applications to grid storage, though this may require additional manufacturing facilities.
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