Getting a grip on Lithium-Ion
Originally created on January 04 2008
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From the sailor – laymen’ perspective Lithium Ion batteries are a dream come true. If it all checks out we can multiply our load capacity in the same allotted space while maintaining our waterline; we can run that horrible diesel a fraction of what we are accustomed to reload our battery banks, and even aspire to rid ourselves completely from the noisy smelly clunker with whom we maintain a symbiotic love hate relationship. But what of the echoes of a glaring side effects: they can short on occasion, in industry parlance initiate a “runaway thermal reaction”, again in layman’s terms a fire capable of burning its way right through the hull.
The noted events of laptop batteries catching fire that have cost companies like Sony a bundle are supposed to be a thing of the past, yet airlines are putting some restrictions on “how much extra power” we can take on board in the form of spare batteries – infinitesimal compared to what we need on board a sailing vessel. On the other hand we can see Li-Ion batteries going into similarly critical applications such as hybrid and electric automobiles, submarines and spacecraft.
In keeping with our crossover logic that implies that development in the hybrid automotive sector is ultimately good for sailboat propulsion retrofits, battery technology is the essential building block for our hybrid rolling and floating stock. In 2008 at least five manufacturers will be commercially launching a variety of Li-Ion batteries for automotive and industrial applications, and likely as many EV, PHEV and Hybrid vehicles will be integrating them over the next six to eighteen months. So somebody must be doing something right.
Comparing batteries in a range of applications in terms of amp hours (an amp hour is a measure of how much power a battery can store), we can look at them from a scale perspective : current Li-Ion notebook batteries are based on small format cells, with each cell providing about 4.4 amp hours of power (conventional notebook batteries provide about 2.5 amp hours), a plug in electric vehicle (PEV) or a hybrid with backup generating power would require batteries with cells that can provide 5 to 10 amp hours.
A number of companies have attained or claim to have surpassed such performance and recent nano-technology breakthroughs have demonstrated the ability to multiply by ten these storage capabilities. Most of the research that has enabled these results are based on variations of the internal chemistry of the batteries, some can already be consulted on this site such as Altair Nanotechnologies and EnerDel who have devised lithium titanate batteries, while others such as Valence have come up with lithium potassium batteries. The change in chemistry lowers the risk of explosions, but also lowers the energy density. But the most exciting aspect beyond the enhanced storage capability, the real paradigm shift, is the ability to recharge the battery in record time, or shall I rephrase by saying that the internal chemical resistance to absorbing charge has been overcome allowing for a multitude of charge sources to be used alone or together, for example solar, plus wind generator plus regenerative sailing using the electric drive motor as a generator, and if it is really necessary starting up the old clunker (until fuel cells come on line — see Voller).
It will be fascinating to see over the next few months how real all these claims are, but it is now more than a probability that anything currently off the shelf will be obsolete before mid year — a close watch of product offerings from companies such as A123, Toshiba, Valence, Boston Power, Panasonic, Sanyo, Continental and perhaps even Saft may knock our socks off. Be assured, greenboat/bateauvert will be at the helm reporting anything we feel of interest coming over the the horizon.
Happy new year to all, it should be an exciting one !
