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Who on ET knows enough to write a diary about why rechargeable batteries both large and small don't live up to expectations? (Battery life, overheating problems, size and weight, etc). Other (battery-using) technologies seem to have progressed much faster over the last twenty-odd years, than battery technology itself. Can anyone explain the reasons?
by afew (afew(a in a circle)eurotrib_dot_com) on Wed Sep 23rd, 2009 at 03:14:29 AM EST
[ Parent ]
Consumer electronics producers really don't have any incentives to lengthen the life of their batteries...

Un roi sans divertissement est un homme plein de misères
by linca (antonin POINT lucas AROBASE gmail.com) on Wed Sep 23rd, 2009 at 03:35:54 AM EST
[ Parent ]
Lithium-ion battery - Wikipedia, the free encyclopedia
Research claims

In April 2006, a group of scientists at MIT announced a process which uses viruses to form nano-sized wires. These can be used to build ultrathin lithium-ion batteries with three times the normal energy density.[55]

As of June 2006, researchers in France have created nanostructured battery electrodes with several times the energy capacity, by weight and volume, of conventional electrodes.[56]

In the September 2007 issue of Nature, researchers from the University of Waterloo, Canada, reported a new cathode chemistry, in which the hydroxyl group in the iron phosphate cathode was replaced by fluorine. [7] The advantages seem to be two-fold. First, there is less volume change in the cathode over a charge cycle which may improve battery life. Secondly, the chemistry allows the substitution of the lithium in the battery with either sodium or a sodium/lithium mixture (hence their reference to it as an Alkali-Ion battery).

In November 2007, Subaru unveiled their concept G4e electric vehicle with a lithium vanadium oxide-based lithium-ion battery, promising double the energy density of a conventional lithium-ion battery (lithium cobalt oxide and graphite).[8] In the lab, lithium vanadium oxide anodes, paired with lithium cobalt oxide cathodes, have achieved 745Wh/l, nearly three times the volumetric energy density of conventional lithium-ion batteries. [9]

In December 2007, researchers at Stanford University reported creating a lithium-ion nanowire battery with ten times the energy density (amount of energy available by weight) through using silicon nanowires deposited on stainless steel as the anode. The battery takes advantage of the fact that silicon can hold large amounts of lithium, and helps alleviate the longstanding problem of cracking by the small size of the wires. [10] To gain a tenfold improvement in energy density, the cathode would need to be improved as well; however, even just improving the anode could provide "several" times the energy density, according to the team. The team leader, Yi Cui, expects to be able to commercialize the technology in about five years.[11]. Having a large capacitive anode will not increase the capacity of the battery as predicted by the author when the cathode material is far less capacitive than the anode. However, current lithium-ion capacity is mainly limited by the low theoretical capacity (372 mAh g−1) of the graphite in use as the anode material, so improvement could be significant and would then be limited by the cathode material instead.

There are trials with metal hydrides as anode material for lithium-ion batteries. A practical electrode capacity as high as 1480 mAh g−1 has been reported.[57]

In April 2009 a report in New Scientist claimed that Angela Belcher's team at MIT had succeeded in producing the first full virus-based 3-volt lithium-ion battery.[58]

Recent studies performed at SUNY Binghamton by M. S. Whittingham et al. determined that vanadium ions can be incorporated into the iron-containing olivine structure of LiFePO4; a small amount of vanadium (around 5%) enhancing the rate capability of the LiFePO4 olivine cathode material. The resulting compound material had higher electronic and ionic conductivities, and they were of comparable magnitude. The doping reaction kinetics were optimal under reducing atmosphere during the synthesis of the LiFe0.95V0.05PO4 material.[59]

Battery tech has improved sigificantly over the last ten years. Back in 2000, Li-ion AA capacity was less than 1000mAh. Now it's getting on for three times that, with room for more improvement. It took about three years to 'productise' the original Li-ion batteries, so some of these developments should be along shortly - assuming they're cheap enough to mass produce.

Car batteries are a tougher problem because the wider temperature range and higher output currents mean more physical, electrical and chemical stress. Car batteries need to be able to handle freezing starts, and I'm not sure how many can do that yet.

by ThatBritGuy (thatbritguy (at) googlemail.com) on Wed Sep 23rd, 2009 at 04:59:14 AM EST
[ Parent ]
Car batteries need to be able to handle freezing starts, and I'm not sure how many can do that yet.

You can just do it like the Russians did: Build your car strong enough to withstand lighting a fire under the engine to melt the oil :-P

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Wed Sep 23rd, 2009 at 05:35:54 AM EST
[ Parent ]
My 5-year old Apple notebook's battery had a useful life of a few minutes, at best, right now

My 3-year old basic Nokia phone still has pretty much the same multi-day battery life as in the beginning.

In the long run, we're all dead. John Maynard Keynes

by Jerome a Paris (etg@eurotrib.com) on Wed Sep 23rd, 2009 at 06:54:31 AM EST
[ Parent ]
Thats probably down to you running the laptop plugged in, the best way to retain battery life is to unplug the laptop as soon as the battery is full, otherwise, running it and minimally recharging causes damage to the battery cells. Modern laptop charging cuircuits will reduce the damage, but dont eliminate it entirely. Your mobile phone will be run mainly disconnected, so this problem wont occur.

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Wed Sep 23rd, 2009 at 07:44:19 AM EST
[ Parent ]
I unplugged my laptop.
by senilebiker on Wed Sep 23rd, 2009 at 07:53:24 AM EST
[ Parent ]
what about removing the charged battery, and putting it back in when needed? will that lengthen life?

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty
by melo (melometa4(at)gmail.com) on Thu Sep 24th, 2009 at 02:09:59 AM EST
[ Parent ]
NiMH batteries as used in hybrid cars have indefinite lifetimes. The charge/discharge cycle only uses about half of the full capacity of the cells, in order to avoid the regions near full and empty that cause the most damage to the chemistry.

They work down to around 0 F (-20 C), below which a regular lead-acid battery is used to start the engine.

by asdf on Wed Sep 23rd, 2009 at 11:26:02 PM EST
[ Parent ]


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