The lowdown on lithium batteries..... the coolest, & hottest battery for tech

L-ion Batterys, (Lithium Ion Batterys), are a pretty amazing piece of technology and very popular. You can find them in cell phones, pdas, laptops, gps devices...etc.

They hold a "higher energy density" per pound. They pack more punch per pound more than any other battery type. Including Nickle Metal Hydide (NiMH) which can be found in hybrid cars like the Toyota Prius and the Honda Insight.
Because of that, the automotive industry is seeing l-ion batterys as a replacement for the NiMH batteries. Currently the Chevy Volt & the Nissan Leaf use the L-ion batteries. Other companies are soon to follow. One big issue they have to tackle is that lion batteries don't do well with extreme temperatures.

So how do they work and what is with them exploding in cell phones?

Background

Lithium by nature is an unstable metal however lithium ions are much safer. 

In 1979, solid state physicist John B Goodenough

discovered that by using lithium cobalt oxide as a cathode of a lithium-ion rechargeable battery, it was possible to achieve a high density of stored energy with an anode other than metal. His last name is certainly ironic! (are they "good enough"?)

In 1991 the Sony Corporation started commercializing lithium iion batterys and L-ion batterys started replacing nickle cadmium batterys (Nicad) in the late 1990s.

How they work

L-ion batterys work by the same principle as any other battery does. The transfer of electrons between a cathode (positive) and an anode (negitive). The only difference is the chemical composition within the cells. And the fact that with rechargeable batteries the charge is reversed as well.

They're also low maintenance which is a big advantage over other battery types. They require no memory so no cycling is required like the old Nicad batteries.

But they do have drawbacks. L-ion batteries have voltage protection circuits to prevent overcharging and prevent cell voltage from dropping to low during discharge. They contain temperature sensors for monitoring battery temp. If a battery gets to hot, the protection circuit sends a signal to the device to shut down to prevent damage.L-ion batteries prefer a partial discharge rather than a deep discharge.
If the voltage drops down to a certain voltage, the cells are ruined.

What's with exploding batteries?

L-ion batteries hold together positive and negative terminals (cathodes and anodes) along with a polymer that separates the two sides. This is all sandwiched together a tightly wrapped container, but instead of a paste which is found in normal batteries, it's a lithium ionized liquid which is extremely flammable. The manufacturing process creates small minute pieces of metal that float in the liquid. These pieces are removed but the manufacture can't completely remove 100% of these metal flakes.

As you may have seen on the news, Samsung recently recalled the ENTIRE production line of their Galaxy Note 7s due to exploding batteries costing the company over 5.3 billion.

There are two scenarios which can cause a L-ion battery to explode

Heat: The issue lies when the battery starts to get hot, possibly from being on the charger....in someones pockets,,,or left on the dash of a car on a summer day.
When that happens the fluid inside the battery becomes thinner allowing the small pieces of metal to move more freely. If a piece of metal comes in contact with the separator, a short circuit will occur. When a short circuit occurs in a flammable liquid it's not a pretty sight.

Aggressive technology design flaw: Or what you could call "pushing the safety boundary" - Cell phone manufactures are always seeking to push more power into smaller batteries and wanting a flatter battery in the design phase. The flatter the battery the thinner the components must be inside the battery.....to a point where the polymer separators may not be effective in separating the negative and positive sides.

This manufacturing error allowed the plates to make contact and a short circuit followed creating an enormous amount of heat to the point where the battery exploded.

If you have a Samsung Note 7,please contact your carrier directly or call Samsung Customer service at 1-844-365-6197 for assistance. Visit Samsung Note 7 recall for further information.

The hazards and issues with lithium batteries are rare. But for their small compact size, they pack a good punch and the tech industry sees anything smaller with more power a big advantage.

Tech History: Wireless charging....the history behind it....and is it worth it?

Your phones battery shows 5% left, so you head out to the living room and plop the phone down onto the wireless charging matt.

It's true...wireless charging has a real "cool" factor....but is it really worth it?....and how exactly does it work?

How it started

Wireless charging is not new, but the technology in in it's current (pun!!) form is. In 1831 Michael Faraday discovered electrical induction during an experiment using two wires wrapped around an iron ring. He expanded on the idea with the theory of "lines of force", but this theory was rejected by scientists of the day due to the lack of mathematical formulas.

Tesla demonstrating wireless transmission of electrical current

Soon after, Nicolas Tesla brought the idea further in 1890, lighting Geissler tubes and incandescent light bulbs across a stage during public demonstrations.

https://en.wikipedia.org/wiki/Wireless_power_transfer#Tesla

Inductive charging works using an electromagnetic field between two objects. a coil in the pad creates a magnetic field which induces a current in another coil, in the phone, charging its battery. The stronger the magnet and the current in the first coil, the increase of the induction and power transfer. There are two different types of wireless charging standards today; Qi and Powermat. They both use the same inductive charging, however the charging rate and current are different.

Is it worth it?

So it's a real cool technology, but it's more like a *"proof of concept" than a major jump in technology where it can be used to a full potential. So before you plop $10-$30 for a charging mat, think about three main disadvantages which involve wireless charging.

1. The mat is the charging platform....so that still needs a source of electricity. But the phone needs to remain on the mat in order to charge......so much for true freedom.
2. The charge/current will still be weaker and slower than directly plugging in your phone to a charger. On the average wireless pads take 25% more to charge a phone than direct cords.
3. The charging mats create heat.....alot of heat. And heat is the evil enemy of cell phones.

The future of wireless charging

It's still in it's infancy, and wireless charging has a lot of potential, especially in the automotive industry.
Were not talking having your car charge on the driveway charging....we're talking about wireless charging your Tesla WHILE your driving!
The UK has already spent $300,000 investigating the feasibility of "Dynamic charging".....electric roadways which charge the car while driving on the roadway. The UK has setup an 18 month trial for the testing.

So wireless charging has alot of potential, and if you find you're walking down the street and you realize you only have 2% before your phone dies you can stop into a Starbucks for a quick charge (enough to get the phone usable), but in the long run.....you'll probably be better off carrying an extra battery and USB cord.

*Proof Of Concept is the realization that an idea, technology or otherwise, has practical potential, but yet the application of the idea or technology has yet to be feasible.