New Electrodes for Lithium-ion Batteries Clear Safety Tests

Altair Nanotechnologies announced today that has completed an internal safety-testing cycle for its new nano-structured negative electrode material - nano Lithium Titanium Oxide (nLTO) - that can replace the graphite used in conventional lithium-ion batteries [see this post at Green Car Congress for more].

Via a course of safety tests conducted over the past few months, Altairnano’s nLTO demonstrated safety under conditions where standard graphite-based cells typically smoke, vent and explode, according to the company. This could help smooth the road ahead for the introduction of Li ion batteries for use in hybrids, plug-ins and electric vehicles. Li ion batteries have both higher energy densities and much better efficiencies than the currently utilized Nickel Metal Hydide (NiMH) batteries currently used in hybirds. Concerns about safety as well as higher initial production costs have slowed Li ion batteries entry into the automotive market [at high production volumes, Li ion batteries actually have production costs equal to or lower than NiMH].

Alan Gotcher, Altair Nanotechnologies' President and CEO had this to say:

"The safety testing cycle that Altairnano has just completed on nano Lithium Titanium Oxide (nLTO)-enabled batteries is a significant milestone in the continued development of HEVs and EVs [hybrid-electric vehicles and electric vehicles] for mass usage, as well as for a diverse range of other applications. We put nLTO to a rigorous and uncompromising set of tests and the results were extremely compelling, in terms of safety, performance and lifespan."

Altairnano performed 'hot-box' exercises on its batteries at temperatures up to 240° C - more than 100° C above the temperature at which graphite-based batteries can explode - with zero explosions or safety concerns.

In addition, Altairnano performed high-rate overcharge, puncture, crush, drop and other comparative tests alongside a wide range of graphite-based battery cells with, again, no malfunctions, explosions or safety concerns exhibited by the nano-structured Altairnano nLTO cells. In comparison, the graphite cells, put to the same tests, routinely smoked, caught fire and exploded.

In addition to the safety enhancements achieved via nLTO, Altairnano’s nLTO battery technology offers improvements, as compared to graphite-based lithium ion cells, to certain measures of cell performance important in the EV and EV market. For example, battery cells using nLTO can be charged in as little as one minute, according to the company, while graphite-containing cells take between one and two hours to charge.

Altairnano has performed tests demonstrating an unprecedented >9,000 use cycles at charge/discharge rates at which other battery types simply cannot function, let alone charge, according to the company. [Note: 9,000 cycles is very good; as of 2004, the best NiMH batteries from Saft got just under 3,000 cycles (discharged between 80% and 20% state of charge). Even at that level though, that's enough to allow a battery pack for an EV or PHEV to last 130,000 driving miles or more. 9,000 cycles could clearly outlast the typical useful life of a vehicle - i.e., 10-15 years and 150,000 miles].

Additionally, Altairnano nLTO-based batteries can reportedly operate at temperatures as low as -50o C and as high as 75o C - again, with no unsafe characteristics.

In March, Altair Nanotechnologies and Electro Energy entered into a four-year Joint Development Agreement for the design, manufacture and marketing of high-power lithium-ion batteries and battery systems.

[A hat tip to Green Car Congress]