Lockheed Martin Purchases Flow-Battery Assets of Sun Catalytix

August 28, 2014 by Jeff Shepard

Lockheed Martin has completed the acquisition of substantially all of the assets of Sun Catalytix Corporation, complementing existing Lockheed Martin capabilities in the area of energy management and efficiency. The purchase includes certain intellectual property, contracts, facilities and the transfer of the company's approximately 25 employees to Lockheed Martin. The terms of the agreement were not disclosed and are not material to Lockheed Martin.

Going forward, the operation will be known as Lockheed Martin Advanced Energy Storage, LLC and will be a wholly-owned subsidiary of Lockheed Martin reporting through the Corporation’s Missiles and Fire Control business area. Sun Catalytix is designing a flow battery for grid energy storage. The MIT spinoff, which had hoped to differentiate itself with a novel chemistry and inexpensive mechanical systems. In late 2013, Sun Catalytix developed a small-scale five-kilowatt prototype. It projected that a full-scale system, which it expected to make in 2015 or 2016, will cost under $300 per kilowatt-hour, or less than half as much as the sodium-sulfur batteries now used for multi-hour grid storage.

The active material in a typical flow battery is a metal, such as vanadium or zinc, dissolved in a liquid electrolyte. To create a current, the liquids are pumped from large tanks into a device where an electrochemical reaction occurs across a membrane. The electrolytes are pumped in the reverse direction to charge the battery. One big advantage of flow batteries is that the amount of energy they store can be increased by simply making the tanks larger.

Sun Catalytix’s electrolytes are made from metals combined with ligands, or molecules that bind to metal atoms. Using synthetic metal-ligand compounds as the active battery materials gave engineers more design flexibility in pursuing an inexpensive, safe battery that can last 15 years with daily charging, according to the company.

In one version of the battery being developed at its lab, two square plates made of carbon-plastic composite, each about as thick as a piece of paper, are stacked with a thin plastic membrane between them to form a cell. During charging and discharging, the two liquid electrolytes travel through grooves carved within each plate to trigger the chemical reaction across the membrane.

The prototype system, held in a glass enclosure, is made up of 50 cells in two horizontal rows, or “stacks.” The cells are not wired individually; instead, the current travels through the plates from one end of the stack to the other, which saves costs on wiring. Below the stacks are tanks of liquid electrolytes, pumps, valves, and tubes made of PVC plastic—all of which is off-the-shelf equipment. A full-scale system would use hundreds of cells, each roughly the size of a pizza box.

One way Sun Catalytix’s batteries are different from more conventional flow batteries, according to the company, is that the active materials are dissolved in a near-neutral aqueous solution that is safe in the case of a spill and not corrosive to pumps and valves. Most flow-battery electrolytes are strong acids, which could cause safety concerns if the technology is used in buildings and can require containment vessels that introduce more cos. Current efforts focus on the design, synthesis and electrochemical testing of a novel energy storage chemistry derived from low cost, earth-abundant materials.