Planar Energy Devices Licenses Separator Technology for Large-Format Li-ion Batteries

11 September 2008

In a licensing agreement with Policell Technologies Inc., Planar Energy Devices Inc., has acquired technology and manufacturing rights for a new generation of safe, large-format prismatic lithium-ion batteries based on a new bondable nano-composite separator technology.

Planar, a spinout of the National Renewable Energy Laboratory (NREL), licenses thin-film battery technology from NREL and Oak Ridge National Laboratory (earlier post) and has two product lines under development: PowerPlane, solid-state thin-film Li-ion batteries; and PowerBlade, large-format prismatic cells in which the Policell separator technology factors.

The new cell and separator technology from Policell has a chemically engineered shutdown feature that prevents cells from triggering thermal runaway. Safely preventing thermal runaway without reducing the capacity and cycle life of lithium-ion batteries has been a major impediment to broader use of lithium-ion energy storage.

In recent years we have seen increasing numbers of high-profile incidents where batteries catch on fire or in some cases explode. The industry has reached a crossroads where traditional approaches to increasing battery capacity have also led to decreasing safety. Planar’s proprietary approach enables a new generation of lithium ion batteries that address both the demands of safety and capacity in a product that can be manufactured in volume.

As laminated flat cell structure rapidly becomes the lithium battery format of choice for many consumer applications ranging from wireless devices to Hybrid Electric Vehicles (HEV) and Electric Vehicles (EV)—safety will be the major impediment to wide scale market acceptance.

—Planar CEO Scott Faris

The core of Planar’s thin-film battery technology is work done at NREL on developing a solid-state, thin-film lithium battery. Thin-film batteries can degrade very quickly, because the lithium metal anode is on the top. NREL researchers had devised a way to electrochemically plate the lithium anode on a lower layer of the battery, forming a “buried” anode.

Battelle Ventures—an independent venture fund that leverages the technologies and expertise of the national laboratories managed or co-managed by Battelle—found the thin-film work at NREL was synergistic with work being done at ORNL to commercialize its own thin-film battery based on a LiPON (Lithium Phosphorus Oxy-Nitride) electrolyte.

With funding from Battelle, NREL demonstrated working prototypes that were durable, and with a high charge capacity. Planar Energy, a startup jointly founded by Battelle Venture and Scott Faris, licensed both the NREL and ORNL technologies. Dr. Roland Pitts, the NREL team leader, is now serving as Planar’s Founding Senior Research Scientist.

PowerPlane is a LiPON thin-film battery (ORNL) but using an entirely different construct (NREL) which makes the battery significantly easier to manufacture and with minimal packaging, according to Faris. PowerPlane batteries are initially aimed at fixed wireless applications, he said.

By contrast, PowerBlade is positioned as a product platform for mobile and wireless applications. The 3.7 V cells offer a specific energy of 220 Wh/kg and energy density of 520 Wh/L. Three initial formats offer capacities ranging from 0.64 to a projected 27.5 Ah.

Both PowerPlane and PowerBlade platforms, said Faris, are enabled by a series of advanced nanomaterials which have high degrees of compatibility. In addition to its integrity over a range of thermal conditions, properties of the new PowerBlade allows Planar to use some proprietary electrolytes as well different cell constructs to enable use thicker cathodes while maintaining high rates.

Long term, you will see some of the features and capabilities of the thin film technology begin to move into this platform which will provides us a even broader set of competitive advantages.

The focus of Planar is to design and build all solid state batteries across the capacity and power ranges. To accomplish this goal, the company has been acquiring key technologies that have significant value on a discrete basis, but in combination, can lead to a true revolution in solid state energy storage. [PowerPlane and PowerBlade] are starting points on a plan to a journey of all solid-state energy storage.

—Scott Faris