Lithium-ion batteries are everywhere, in all our modern devices we use on a daily basis. So much so I hadn’t given much thought to the fact that I don’t know much about lithium-ion batteries, how they work, or what lithium even was! (High school chemistry lessons clearly sunk in…)
Clueing myself up and recapping for everyone else, I present; The Li-ion for Dummies Starter Pack
Firstly, let’s begin with…
What is Lithium?
Lithium is a soft silver-white alkali metal, which in standard conditions is the lightest metal and the least dense solid element. Its chemical symbol is Li and atomic number is 3. It is the first member of the alkali metal family.
In density it is comparable to pine wood yet it is so soft it can be cut with a knife. Like all alkali metals it is highly reactive and flammable.
Never occurring freely in nature, lithium only appears in compounds. It is present in ocean water and is most commonly obtained from brines. Trace amounts of lithium are present in all living organisms (apparently lithium in drinking water could extend human lifespan but that’s not our business here at Dukosi).
Okay, that all makes sense, but where do we get lithium?
Lithium deposits are mainly found in the Americas with Chile and Argentina being the leading producers. The lithium is extracted from brine/saltwater pools. There are also deposits found in Bolivia, in the Andes Mountains, Nevada and Wyoming. Extraction is complex, you can read about it here.
When were lithium batteries invented?
In the 1970s at Oxford University, John Goodenough (actual name, how fantastic?) and his colleagues; Phil Wiseman, Koichi Mizushima and Phil Jones, pioneered lithium-ion in power packs.
It took big corporation, Sony, to turn it into a commercially viable technology. Sony started producing li-ion batteries in the early 1990s.
Why are they so popular?
Lithium-ion batteries have gained popularity over other rechargeable batteries due to their high energy density, good charge times and high number of discharge cycles. It also doesn’t need to be fully discharged to recharge, in fact they prefer partial discharge to deep discharge. This is particularly useful for high performance devices from mobile phones to electric vehicles to large energy storage solutions.
There are some negatives to lithium-ion; it is quite sensitive to cell temperature, which has to be monitored. Also, the batteries don’t age very well, most li-ion batteries last between 5-10 years – however, with advancements in technology this is improving. Our own technology, Evoic is part of the improvement of lithium-ion batteries!
As battery technologies go, li-ion batteries are fairly environmentally friendly. They don’t contain cadmium, a toxic, and heavy metal, like most batteries and have second-life usage. Electric vehicle batteries are being tested to help with large energy storage systems, such as grid storage.
Wait a second… let’s take a few steps back
How does a lithium-ion battery work? Or how does a battery work for that matter?
Let’s start with how a battery works. A battery is a device that stores electrical energy then delivers this energy through an easily controlled electro-chemical reaction.
Lithium-ion batteries use power generating components or cells, like any other battery, made up of a positive electrode, a negative electrode and an electrolyte.
When charging up a li-ion battery the positive electrode feeds some of its lithium-ions to the negative electrode by moving through the electrolyte. The ions stay in the negative electrode and the battery stores the energy until it is needed.
During this process, electrons flow in the opposite direction to the ions around the outer circuit. Electrons do not flow through the electrolyte; in this instance it is basically an insulating barrier.
As it is a rechargeable battery this means the chemical reaction is reversible. When discharging a lithium-ion battery, the battery gives out power rather than storing it.
Lithium-ion batteries need to be made into ‘smart’ batteries using a BMS (battery management system), meaning they have controllers to regulate the charge and discharge, this helps prevent overcharging and overheating – which is useful with a reactive metal. In rare cases, lithium-ion batteries can explode and go on fire. Trust me, it’s rare.
There we have it, a back to basics, introductory level, Li-ion for Dummies Starter Pack!