By Jason Deign
California start-up Capacitor Sciences claims to be developing an energy storage medium that could beat lithium-ion batteries on performance while costing around USD$100 per kWh.
The Menlo Park firm is hoping to use nano-structured crystalline thin films as the dielectric material for capacitors with up to 10 times the energy density and 100 times the power density of lithium ion batteries, according to a press release.
Capacitor Sciences says the use of thin film should overcome problems dogging other capacitor manufacturers, such as ill-fated EEStor, which used inorganic dielectric materials too brittle to withstand repeated charging cycles.
“No-one is really working on this class of materials,” said Wolfgang Mack, vice president of business development. “We’re using organic materials. They are waxy in nature. There’s no damage done during charge and discharge.”
Capacitor Sciences’s founder and chief technology officer, Dr Pavel Lazarev, was previously involved with Crysoptix, a liquid crystal display optical films maker, and nanomaterials business Optiva, which went out of business in 2005.
Hoping to bring in $11m
His latest venture has already raised $4m from angel investors over the past year, Mack said. The company is hoping to bring in to $11m in series A financing in the next couple of months.
This funding should last for up to a year and a half and allow the business to complete manufacturing capacity for thousands of cells along with associated power electronics, according to Mack.
“We’re aiming a parity with lithium ion in energy density, but a much safer product,” he said.
The company, which has 14 patents pending, is initially aiming for an energy density of around 250 watt-hours per kilo, said Mack.
It also has a two-year roadmap for achieving energy densities of up to 1,000 watt-hours per kilo, he said, or four times current lithium-ion battery levels.
Much higher energy densities
“In the first year we’ll hit 250, in the second we’ll hit 1,000, and then there are possibilities of much higher energy densities depending on how far we can push the permittivity of the material,” he told Energy Storage Report.
As well as being safer than lithium-ion batteries, since the capacitors would not be likely to catch fire, Capacitor Sciences hopes its products will have much longer life spans. They will likely come with a 20-year warranty, Mack said.
At the moment, however, there is still some way for the company to go. Mack admits the company is “in R&D, more in R going to D shortly.”
Over the next couple of months the firm is hoping to sign up strategic investors that can help it commercialise products, but backers will be wary of previous challenges with capacitor technology.
Attracting attention from major investors
EEStor, for example, made grand promises about its capacitor technology but had problems proving them after raising at least $7.5m from ZENN Motors and an undisclosed amount from venture capital firm Kleiner Perkins.
The publicly quoted company, now merged with ZENN, has been trading under CAD$0.50 a share for more than a year. QuantumScape, another capacitor developer, attracted attention from major investors including Volkswagen.
But the outcome of a decision by the carmaker last July over whether to pursue the secretive start-up’s solid-state batteries was never disclosed, and it is unclear whether QuantumScape is still pursuing its original technology.
Mack said the companies simply chose the wrong kind of dielectric materials. Backers will still need to be convinced this is the right kind of storage technology to put money into in the first place.