To fully understand and appreciate the lithium-ion battery, let’s first understand the constituents of a typical lithium-ion battery.

The lithium-ion batteries consist of lithium cobalt oxide (LiCoO2) as the positive electrode and graphite as the negative electrode. The electrolyte widely used in most lithium-ion batteries is dimethyl carbonate. When the batteries charge, the lithium ions and electrons migrate from the positive to the negative electrode. They discharge, the ions and electrons move from the negative to the positive electrodes, powering its host gadget (phones, laptops etc…). The ions move through an electrolyte typically made of lithium salt dissolved in an organic liquid.
Factors that account for certain accidents in lithium-ion batteries;
Short- circuiting:
A porous separator keeps the battery electrodes apart. Charging the battery for long period or inflicting a mechanical blow can damage the separator thereby causing the battery to discharge rapidly and generate a lot of heat which can in turn melt the battery and subsequent fire.
Over-charging:
When over-charged, lithium cobalt oxide releases oxygen. This can react with the flammable electrolyte and also with cobalt oxide (Co3O4) left over after the release of oxygen. Note that cobalt oxide also increases the resistance of the battery raising the risk of over-heating which will in turn result to more severe implications such as explosion and fire.
Electrolyte breakdown:
The common electrolyte substance used in the lithium-ion battery is the Dimethyl carbonate.
During charging, some of the organic molecules in the electrolyte can break down, forming carbon dioxide. Because the battery is sealed, this causes the pressure to build up. When the pressure is high enough, the battery bursts exposing the flammable electrolyte. This in turn can lead to fire occurrence as in the case of the new Samsung galaxy Note 7. This phenomenon goes a long way to explain why it is advised to unplug gadgets from mains while answering phone calls.
Why the continued usage of lithium-ion battery?
Well, lemme try and answer that question too. There are a few reasons why the lithium-ion battery is still a darling to most manufacturers, and here are some;
1.Lithium is most preferred because it retains more charge
2.Lithium has better energy density on both volumetric (size) and gravimetric (mass) basis. In other words, you get more for the battery size and weight than other competing alternatives.
3.The closest alternative presently require multiple cells and have half the energy density of the former making it less economically viable for commercial purposes.
There are quite a few alternatives to the embattled lithium-ion battery, the list is encouraging enough even though research is still ongoing to improve the safety of the present one. Some of the options that may be adopted when the time is right are Nickel-cadmium, lithium ferrous tetraoxophosphate (which is less prone to oxygen loss, but consumers prefer lower energy density), sodium-ion battery, lithium-air and lithium-sulphur(more for electric cars). Also, significant progress has been made to replace organic electrolyte with possibly ceramic. If that is done, then lithium-ion will be even much safer and better than any other there may be.
Until then, we on nairaland will have to be more safety conscious with the handling of our gadgets. As much as they help us get around our daily engagement, they can also ruin it. Feel free to point out any omission or commission that you may observe to help improve the article.

SAUCE? Accumulated research and observations and my current research project.

hmmn.