How do Batteries Work?

There are numerous types of batteries, and due to the structure of a battery, each comes with its own unique own dangers. The internal structure of a battery is composed of the anode, the cathode, and an electrolyte solution. The anode and cathode are just fancy names for two metals, one with a negative and positive charge, respectively. Two separate chemical reactions occur at both the anode and cathode with the electrolyte solution, which allows for the harvesting of electrons, which are responsible for electricity. The potential of batteries comes down to the various metals which are used as part of the cathode, anode, or eletrolyte solution. Batteries that give off higher charge often need to be increasingly reactive, which make them relatively dangerous, especially when they are not disposed of properly.

Hence, the main danger of carelessly throwing away batteries revolves around the reactions that take place between the batteries' metals and other substances, and what those new compounds can do. Learn what metals and substances are involved in each type of battery and learn how to recognize them below.

Alkaline (“General Purpose”)

  • These are the standard batteries that are used everyday (A, AA, AAA, 9-Volt, C, D, etc.). Most companies label them.
  • It is safe to throw these out as long as they’ve been made after 1993. Prior to 1993, these batteries had Mercury inside of them, which is a very heavy metal, but nowadays, the metals involved are relatively harmless. While they CAN be recycled, there is currently no cost efficient way to recycle them. If they do contain Mercury, call your local recycling center for more information and instructions on how to dispose of them.


  • These batteries include lithium ion, nickel metal hydride, nickel cadmium, and lead acid batteries. They are, as the name describes, rechargeable, so they shouldn’t be difficult to pin-point.
  • Rechargeable batteries are their own separate category, despite containing chemicals similar to lithium primary batteries, because their structure is modified to allow for “recharging"; each battery has to be designed to reverse the natural process of harvesting electrons, a process called an 'electrolytic' reaction, making the design and substances involved more complex and potentially more dangerous.
  • Lithium ion and nickel metal hydride batteries are typically non-toxic, so they can technically be thrown away safely. However, it is highly recommended that you recycle rechargeable batteries because of the other more hazardous chemicals that may be involved.
  • Nickel Cadmium (NiCd) - The main problem with these batteries is the emission of Cadmium when they are improperly disposed of. The batteries end up in landfills and contaminate the soil and nearby streams. This also affects humans through the consumption of contaminated fruits and vegetables as well as the consumption of contaminated meat. Inhaled Cadmium can damage the lungs and consumed Cadmium can damage the Kidneys, which in turn affects numerous other bodily systems.
  • Lead - This is a toxic metal that can also contaminate the soil if thrown out with other regular garbage. Lead poisoning can cause developmental problems in younger kids, cause brain damage, nerve problems, and more.

Lithium Primary

  • Lithium batteries will be labelled as “Lithium” batteries, and they are non-rechargeable. Lithium can react relatively violently with moisture in the air and water, and it can combust, creating landfill fires. Because of this, it is recommended that these be recycled, especially when discarded in large quantities. Below is a slow motion demonstration of lithium burning underwater.

Cell Phones and Tablets

The way that cell phones and tablets look can be a bit deceiving. They have so many capabilities, yet they manage to stay contained in a small little box. Underneath that cozy little packaging is not only a complex network of connections and circuitry, but also a plethora of precious metals.

Besides the lithium ion battery that most phones are equipped with (which should be dealt with separately as mentioned previously in the “Batteries” section), phones and tablets are made of a variety of metals that are both expensive and irreplaceable. For example, gold, platinum, silver, copper, etc. are found in trace amounts in phones. While the amount present of these metals in a single phone may seem insignificant, the expenses incurred to dig up these metals (many of which are mined in open pits using sulfuric acid, which is not environmentally friendly) are beyond astronomical.

It should also be noted that these technologies do contain some heavy metals that are dangerous to throw away, but these will be discussed in a separate section.

On top of these valuable metals, cell phones and tablets are also composed of a number of “rare earth metals”, which cannot be mined using traditional methods. They are also available in limited quantities in nature, meaning that every little bit that is thrown out is that much less available for use in the world. And since there are few if no substitutes available, throwing away cell phones is literally digging a hole for future generations.

What you can do

  • Recycle It: The obvious solution is to recycle these devices. This can be usually done at the local electronics or phone store. Often times, you can turn in it in, sometimes even for credit on your next phone, and the stores will recycle it for you.
  • Sell or Donate: After deleting all personal information, you can sell your old phone for some money; there's definitely a market for cheap, used phones. You can also choose to donate it to various organizations that would put it to better use.

Computers & Laptops

Computers and Laptops often suffer from similar problems of phones and tablets; there are many metals in the internal workings of the computer that are valuable and can be recycled. For example, the CPU has a number of gold pins, copper wires, etc. However, computers and laptops also have a large number of heavy toxic metals and other substances that should definitely not be disposed through regular means.

Just to name a few heavy metals, lead, cadmium, mercury, and chromium are all found in computer parts; they are not only carcinogenic but also hard to break down. Lead and cadmium are discussed in the batteries section while plastics and chromium are discussed below.

Plastics - Computer casings are often made out of plastic, and certain computer parts are also laced in plastic. Plastic is well-known to not decompose naturally; it stays in natural systems for extended period of times, causing harm to the environment.

Chromium - Chromium takes different forms, each form taking up different chemical properties. The toxic form is called Chromium(VI), which has the ability to alter genetic code and cause cancer, making it a carcinogen. Chromium(VI) is often found in computer monitors, and when monitors are thrown out, it seeps out into the soil and into the water. Since Chromium(VI) is toxic to both humans and many other organisms, it can be devestating to many different life forms in affected areas.

What you can do

  • Recycle Parts: Often times, when a computer 'breaks', only one part of the computer is malfunctioning. If you can pinpoint the broken part and find a way to replace it, you can fix your computer, save money, and help preserve a little bit of the environment. This approach is probably not as effective for laptops due to their compact form.
  • Recycle Computers: If your computer breaks and you find that it will be more expensive to replace the broken part than to buy a new one, consider sending it back to the manufacturer for recycling. Sometimes, manufacturers will even provide a cash incentive to do this. You can also sell it to local repair shops - they often scrap computers for parts that they can reuse later.
  • Donate: If you bought a new computer simply because your other one was 'outdated' or 'old', then consider donating your functioning ex-computer to a charity or someone who could make use of it.

Televisions (tv)

TV’s fall into the same category as computers and phones in that they contain many heavy metals and valuable metals that can be recycled. Below are a few types of TV’s and the chemicals involved. An emphasis on this section is placed towards which TV type is the most environmentally friendly.

Liquid Crystal Displays (LCD)

LCD TV’s work by utilizing two layers that are laid on top of one another. The first layer is called the backlight, and it does exactly that, provides light to the second layer. The second layer is the actual “liquid crystal display”. It works as a type of filter on a pixel basis. An electric current is run through the pixels of the LCD, and based on the electric current, the opacity of the pixel is controlled. The two main types of LCD TV’s are CCFL and LED TV’s.

Cold-Cathode Fluorescent Lamp (CCFL)

  • This is the type of TV that people usually refer to when they say LCD. The primary difference between this and LED is the backlight. The backlight in this case uses cathode tubes, which make the TV bulky and more expensive. Due to these qualities, CCFL TV’s are running out of fashion, but they still exist in many homes today.
  • Of the three models discussed here, this is arguably the most inefficient. These TV’s contain Mercury, which can cause brain damage. In the manufacturing process, they also create Nitrogen Trifluoride, which is a Greenhouse Gas. Also, unlike LED models, these TV’s still use fluorescent lighting, which is comparatively energy inefficient.

Light Emitting Diodes (LED)

  • While these TV’s are often called “LED”, they are actually just a type of LCD TV with a different backlight. The backlight uses LED’s to emit light to the LCD. LED’s are more energy efficient, smaller, and more cost efficient, so these are much more preferrable in the modern world.
  • This model is more environmentally friendly than the CCFL counterpart. While the chemical makeup is similar to CCFL TV’s, the primary differences are the LED backlight and the smaller design. Since it’s smaller, less materials are used. The LED’s are also more energy efficient than fluorescent lighting.


  • Plasma Screens have pockets of gas within the screen itself (typically noble gases like Neon and Xenon). The gases are excited, changing them into a plasma state where they emit UV rays. The UV Rays are then absorbed by the pixels, and depending on the intensity of light, the brighter the colors become.
  • Plasma screen TV’s are known for being terribly energy inefficient; however, as the screen gets larger, they’re not much worse than LCD’s. Plasma screens are also known for usually containing Lead; they also have a shorter lifespan than LCD TV’s.

What you can do

  • Recycle: Recycle: If the TV is broken, then you can call the local waste center to pick up the TV. They salvage the parts and eliminate any of the heavy metals. Some states actually make it illegal to throw away TV’s through other means.
  • Donate or Sell: If the TV is still working, then you can either donate it to a non-profit organization for others to use or gain some money by selling it online.
  • Return the TV to the store: Some electronics stores have offers to recycle TV’s for free or for a low price. Sometimes, you can also send the TV back to the manufacturer, who will salvage the parts.
  • Buy the right TV: The above TV models are some of the more common modern formats. It’s high suggested that you purchase a medium sized LED lit TV that is certified by Energy Star. This is because, in comparison, Plasma Screens simply don’t last as long, and they’re more likely to need replacement in a short period of time.