快猫短视频

FLOWERY bundles of carbon nanotubes could one day help your laptop鈥檚
batteries last ten times as long, a meeting celebrating the 10th anniversary of
the nanotube will hear next month.

Conventional fuel cells are powered by the electrical energy released when
hydrogen and oxygen react on specially prepared electrodes. The surface area of
these electrodes is a major factor limiting the reaction speed鈥攁nd hence
the fuel cell鈥檚 power output. 快猫短视频s had hoped to boost fuel cell efficiency
by replacing the electrodes with masses of carbon nanotubes, which are created
when sheets of graphite are rolled up into cylinders. But it鈥檚 tough to get the
gases into the tiny tubes, which are just a few nanometres wide.

Now Sumio Iijima of NEC, who co-invented carbon nanotubes in 1991, has an
answer: carbon nanohorns, in which the carbon tubes taper to a cone-shaped cap
at one end and remain wide open at the other. Nanohorns bunch together at their
tips, forming flower-like bundles hundreds of nanometres across. When these were
used as the electrodes in a fuel cell, Iijima found their much larger surface
area gave energy capacities ten times higher than lithium cells, size-for-size.
NEC will tell the meeting in Tsukuba, Japan, that when fully developed, laptops
using the new cells could theoretically run for 鈥渟everal days鈥� on one charge.