Dead batteries are the worst. Once they're all used up, I have to find a place to recycle
them and keep them around until… BLAHRGH. Why aren't all batteries rechargeable?
We've spent a lot of time on DNews talking
about batteries, and usually it's about how much they suck, but maybe we're not giving
them a fair shake. There's a lot of technology going into these tiny powerhouses.
The first true battery was invented by Alessandro Volta in 1800, and he called it the voltaic
cell, a term we still use today. All batteries, even Volta's original ones, have an anode,
electrolyte and cathode. The anode (neg) provides electrons to the electrolyte, through a chemical
reaction, then the cathode (pos) absorbs the electrons from that electrolyte! If you're
like me, this is the opposite way you expected power to flow, from negative to positive…
but, hey, science!
Batteries you see a lot: AA, AAA, C, D cells… are all alkaline batteries: which means the
cathode is made of manganese dioxide, the anode is a zinc power; the electrolyte is
a potassium hydroxide -- which is the alkali part. Alkali solutions are basic. Not, like,
basic the insult, but basic as opposed to acidic. Battery acids have a high Ph, which
makes them an alkali. Ph is a way to describe a solution in chemistry as either acidic or
alkali; P for Power and the H symbol for Hydrogen. Alkali battery acids have high levels of Hydrogen
ions -- H-plus -- the ions suck the electrons from the negative anode, and then the positively
charged cathode sucks them from the electrolyte. Boom! You've got a battery! When these anodes
and cathodes are connected through -- say -- a flashlight or cell phone, the electrons
streaming from the anode to the cathode are what is powering the device. Eventually, in
a regular battery, the anode gets corroded, the chemical reaction is spent, and the battery
is dead.
SIDEBAR: Sometimes, hitting or shaking a near-dead flashlight makes it brighten. This is due
to the nature of chemical reactions in batteries. The electrolyte is corroding the anode, and
when you smack it the chemical reaction briefly kicks it up a notch. You can't do this forever,
but it's not just in your head, it does help a little!
Non-rechargeables are called primary cells, and rechargeable batteries are called secondary
cells. Once a primary cell is dead, it's pretty much dead. But when you plug a secondary cell
into the wall, the charger forces electrons to stream the opposite direction, recharging
the battery! You could plug in a primary cell, but when you try and force electrons back
through, the chemical reaction doesn't reverse as efficiently. In alkaline batteries, this
can cause the electrolyte solution to generate a hydrogen gas in a confined space until {explosion
noise}! So don't do that.
Most secondary cells you're going to come in contact with are Lithium Ion. Engineers
use lithium in a lot of batteries because it's a highly reactive element. Lithium-Ion
secondary cells use Lithium cobalt oxide as a positive cathode, and simple carbon as an
anode. With a combination of elements, electrons can be pushed back and forth from the carbon
to the lithium and back again many times, though not indefinitely. Batteries in your
phone, for example, can only be recharged a couple hundred times and they'll slowly
hold fewer and fewer electrons.
The reason secondary cells can take the heat and recharge, while primary cells can't, has
to do with the elements chosen, and a bit of 200-year-old chemistry. Primary AA batteries
use cheaper materials like manganese and are great for low-draw devices like flashlights,
and smoke detectors. While lithium is more expensive and great for high-draw devices
like computers and phones. Thats why you don't see AA-sized Lithium-Ion batteries. Nickel-Cadmium
is an affordable middle-ground, with some voltage and some capacity for cameras and
smaller devices where Lithium Ion isn't practical! (If you're curious, nickel is the cathode,
and cadmium is the anode)
When it comes to computers and devices that use Lithium Ion batteries, they probably have
another thing in common, Intel. Having Intel inside makes for better experiences outside.
Intel creates the breakthrough technologies that make amazing experiences possible, driving
innovation in processors, wearables, data centers and devices for the internet of things.