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Samsung Nanotech Breakthrough Nearly Doubles Li-Ion Battery Capacity
The Korea Times reports that Samsung researchers have published in Nature Communications the results of research (here's the abstract) that could lead to vastly greater storage capacity for lithium-ion batteries. The researchers, by growing graphene on silicon anodes, were able to preserve the shape of the anodes, an outcome which has formerly eluded battery designers: silicon tends to deform over numerous charging cycles. From the linked abstract: Here we report direct graphene growth over silicon nanoparticles without silicon carbide formation. The graphene layers anchored onto the silicon surface accommodate the volume expansion of silicon via a sliding process between adjacent graphene layers. When paired with a commercial lithium cobalt oxide cathode, the silicon carbide-free graphene coating allows the full cell to reach volumetric energy densities of 972 and 700Whl1 at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial lithium-ion batteries.
Also at ZDNet.
That's not what it says. It says that the capacity at 200 cycles is 1.5x a current cell. No mention is made of the point at which the capacity of these cells drops below the capacity of regular cells, if indeed such a point even exists: it's entirely possible these cells have roughly the same performance vs cycle curve as current cells after 200 cycles, just with a generally higher capacity.
I suppose you might raise the question of why they limited their testing to 200 cycles rather than more, but I note that if each charge/discharge cycle takes 4 hours then 2000 cycles would take almost a year to complete.
The value of 1.5 is equal to 2 for small values of 2.0
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
Back in the late nineties I had a phone that lasted 2 weeks on a charge. I ended up buying a second charger to have at work because twice a month my phone would die in the middle of the work day. Now I charge my phone every night and that doesn't happen anymore.
I'll take the thinner phone, thanks.
"I like to lick butts!" by MobileTatsu-NJG (#32700246) (Score:5, Informative)
There's news like this every week. None of these is clearly better cheaper or faster to market than any other breakthrough like it at this early stage. It all evens out to a fairly steady improvement over time. Battery weight and prices still keep halving every five years or so and that's already factored into stock prices, minus some risk.