ActaCell: Having raised $5.8 million in a Series A round led by DFJ Mercury and joined by Google.org in 2008, ActaCell has been working toward a 2010 commercial launch. ActaCell’s devices, which it expects to have a longer cycle life at lower costs than the competition, are based on technology developed at the University of Texas at Austin. The company joined the National Alliance for Advanced Transportation Battery Cell Manufacture, a group of 50 U.S. companies that plans to invest more than $600 million in a battery R&D center in Kentucky, if DOE funds come through. In the meantime, the Texas Emerging Technology Fund has awarded the startup up to $1 million in funding that commits ActaCell to locating in Texas a “substantial percentage” of the work covered by the award.

Amprius: Amprius, founded in May 2008 in Menlo Park, Calif., is working on materials for advanced batteries. Backed by VantagePoint Venture Partners and Trident Capital, Amprius also snagged funding under the National Institute of Standards and Technology’s Technology Innovation Program (TIP) last month.The TIP funds, which require Amprius to come up with a matching amount for the project from private sources, will support development of a continuous manufacturing process for a silicon-based anode material for lithium-ion batteries (Amprius currently cranks out small batches of silicon nanowires — if successful, the TIP project will enable production of these nanowires “by the mile”). The idea is to build a battery with higher energy density using nanostructured silicon instead of graphite for the anode material.

Atieva: Founded in 2007 by former Tesla Motors VP Bernard Tse and Astoria Networks founder Sam Weng, Atieva is working on software for monitoring individual battery cells, mechanical packaging and controls for vehicle battery packs. Using commodity cells, Atieva aims to produce customized packs primarily for smaller, independent car companies. The startup secured just over $7 million in financing last month, and its backers no include Beijing’s China Environment Fund III and Venrock Associates.

Boston-Power: Founded in 2005, Boston-Power supplies upgrade batteries for Hewlett-Packard laptops. But nearly a year ago CEO Christina Lampe-Onnerud told us the company was working on a battery for plug-in vehicles. In May, the startup unveiled a battery for plug-in vehicles and said it was in discussions with range of potential transportation customers. Near the end of 2009, Boston-Power joined a new coalition of companies funded by the Swedish government to develop electric vehicles — the first real evidence the startup had made headway with an automotive customer. But whether and how that project will go forward remains uncertain (the company has declined to answer our questions on this topic), since the automaker involved in the group is Saab, the loss-making Swedish division of General Motors that’s on the verge of a wind-down.

CFX Battery: Co-founded in 2007 by Rachid Yazami, research director of France’s National Center for Scientific Research, Caltech professor Robert H. Grubbs and French chemist Andrew Hamwi, CFX Battery is working with technology developed at Caltech to produce prismatic (flat), cylindrical, thin-film and coin lithium-ion cells. The Azusa, Calif.-based startup raised $15 million in its first round of financing, with investors including CMEA Ventures, Harris & Harris Group and U.S. Venture Partners. In August 2009 the company secured $5 million of a planned $27 million Series B round, according to an SEC filing (CFX has not announced additional equity financing since then). Over the next three years the startup plans to focus initially on lithium batteries, and later expand into components and materials for the devices, CFX chief executive Joseph Fisher told Think Equity.

Electrovaya: Mississauga, Ontario-based Electrovaya makes battery systems (cells, modules and interfaces) for hybrid and electric vehicles — including some of its own, such as the low-speed electric Maya 300 that rolled last year in a small ExxonMobil-backed car-sharing program. Working with nanostructured lithium-ion polymer technology, Electrovaya snagged three deals with Chinese manufacturers in late 2008. The firm also has agreements with India’s Tata Motors and Norway’s Miljø Innovasjon for highway-speed electric cars, and it announced plans to form a joint venture with India’s Hero Electric last month to build lithium-ion batteries for the Indian market as well as exports. The company was founded in 1996 and began trading on the Toronto Stock Exchange four years later.

Enax: Founded more than a decade ago as a battery consulting service in Tokyo, Enax is now working on “lithium-ion cells especially for future hybrid and electric drives in automobiles” with battery giant Continental, which bought a 16 percent stake in the company in 2008, among other partners. Enax claims the new batteries will be safer and have a longer service life than today’s offerings, as AutoblogGreen reports. The company, which aims to provide batteries for “electric vehicles, submarines, fuel cell system, etc.,” also supplies electrodes to other companies.

Envia Systems: Based in Hayward, Calif., early-stage Envia Systems raised a $3.2 million first round of financing late last year from Bay Partners and Redpoint Ventures to help with development of low-cost cathode materials for vehicle batteries. The startup entered an elite group last fall: the 1 percent of applicants awarded a first-round grant under the Department of Energy’s high-risk energy tech fund, ARPA-E (Advanced Research Projects Agency-Energy). With its $4 million award, Envia co-founder Michael Sinkula said the company will expand its focus to include anode (or negative electrode) technology. Working in collaboration with the Argonne National Laboratory on the DOE-backed research, Envia aims to develop a prototype of a non-graphite anode for vehicle batteries.

ETV Motors: Founded in 2008, Herzliya, Israel-based ETV Motors is working on propulsion technology for extended-range electric vehicles, encompassing advanced batteries and a microturbine for power generation. The startup raised a “milestone-driven” $12 million investment from 21 Ventures and David Gelbaum’s Quercus Trust in the second half of 2008, and it says its main research focus right now is demonstrating that it can overcome oxidation and other challenges associated with high-voltage spinel cathodes.

Farasis Energy: Farasis Energy is betting that a combination of low manufacturing costs in China and advanced tech expertise in the U.S. will lead to lithium-ion cells that can compete on a global mass market. CEO Yu Wang told us in an interview at IBM’s Almaden Institute in San Jose, Calif. last summer that the Hayward, Calif.-based startup was close to having a factory ready in China for pilot-scale production of its lithium-ion cells. Founded in 2003 by Wang and Keith Kepler, President and CTO (both directed research at now-defunct battery maker Polystor), Farasis has raised venture capital from Chinese investors and at least $750,000 under the DOE’s small business innovation research program.

Flux Power: Based in Vista, Calif. and headed up by Chris Anthony (co-founder of three-wheeled electric vehicle developer Aptera), Flux Power plans to market modular systems for a range of energy storage applications, including electric vehicles and backup power supplies. It’s starting with a charger and a lithium ion battery module, unveiled in November. 

K2 Energy Solutions: Quietly working on rechargeable battery systems since 2006, K2 Energy made the ambitious projection back in 2008 that it would see revenue grow to $30 million in 2010, up from just $2 million that year. We’re not sure if the company is on track to reach that target this year, but recently signed on a large partner — Universal Power Group, or UPG,  that could help it grow. UPG plans to market, distribute and sell the startup’s full line of lithium iron phosphate products.

Leyden Energy: Based in Fremont, Calif., Leyden Energy (formerly known as Mobius Power) aims to produce lithium-ion batteries with high energy density for mobile phones, notebook computers, backup power for the grid, and hybrid vehicles. Founded in 2007 with a reported $4.5 million investment from Walden International, Lightspeed Venture Partners and Sigma Partners (and a patent for uniform cell heat distribution acquired from chemical giant Dupont), the company is working on a battery that it says can handle high temperatures without degrading.

Nexeon Limited: Spun out of London’s Imperial College in 2006, Nexeon is working on silicon-based anodes for lithium-ion batteries. The startup raised 10 million pounds (about $14.2 million) early last year and 4.25 million pounds (about $6.9 million) in July 2007.

Sakti3: Sakti3’s technology stems from research led by CEO Ann Marie Sastry, who heads up University of Michigan’s energy systems engineering program. The Khosla Ventures-backed startup has won significant support from the state of Michigan and partnered with General Motors, a vote of confidence in the startup’s cell tech. In a separate deal, Sastry is helping to retrain 50 GM engineers at the University of Michigan. To reach commercial-scale manufacturing within three years, Sakti3 requested $15 million from the Department of Energy’s battery grant program, but those funds have not come through so far.

Seeo: Seeo has developed a nano-structured solid-state battery based on a solid polymer electrolyte that founders worked on at Lawrence Berkeley National Labs and began licensing from the lab in 2007. Founder and technology director Mohit Singh says the batteries can deliver 300 watt-hours per kilogram (compared with less than 200 watt-hours per kilogram for a traditional lithium-ion battery) and can operate at a much higher temperature than the competition. The company has raised more than $10.6 million, with investors including Khosla Ventures.

Planar Energy Devices: Planar has told us it plans to pursue opportunities in micro, mid-sized and large batteries — starting with military applications and smart cards. The company’s thin-film batteries, designed with a “laminated safety separator” that Planar says protects cells from thermal and overcharge abuse, are supposed to charge in seconds, have a high energy density, last 400-500 life cycles and be safer than traditional lithium-ion batteries. Founded in 2007 as a spin-out from the National Renewable Energy Laboratory, Planar is working on solid-state, high-capacity batteries. Backed by Battele Ventures and Innovation Valley Partners, the startup requested $56 million in DOE stimulus funds last year to support a Gainseville, Fl. manufacturing facility. But Planar has not been among the stimulus winners.

Porous Power Technologies: Colorado-based Porous Power is working on a coating for lithium-ion battery cells that can be used instead of a film insert “to keep various elements in contact with each other but apart,” Greentech Media explains. According to the company’s web site, the high porosity of its so-called Symmetrix separators “reduces resistance within the battery, allowing for faster cell charge and discharge.” The startup has raised $3.5 million and GTM reports that it hopes to raise another $2 million.

Prieto Battery: The brainchild of Amy Prieto (pictured) an assistant chemistry professor at Colorado State, Prieto is the first startup launched out of the business arm of the university’s Cenergy program for commercializing clean energy research. Prieto Battery aims to produce lower cost, higher power density lithium ion batteries using a nanowire-based anode, with prototype No. 1 targeted for early 2010.

Quallion: Although Quallion has been around since 1998, making lithium-ion cells and batteries at high volume for medical and military applications, and in custom designs for aerospace and other applications, the company is a relative newcomer to the plug-in vehicle battery market. It requested $220 million in stimulus funds from the DOE to build a factory in Palmdale, Calif., with capacity to produce 20,000 lithium-ion batteries a year for hybrid cars and trucks by 2012.