Hello geeks of all nations! Hope you’re swell and if not, let me brighten your day with a brand-new article in the Energy Storage Systems series. Today we’re going to talk about the star of storage systems, the cream of the crop, the bestest of them all:

Lithium-ion batteries

The Technology

So, what is a Lithium-ion Battery?

In order to understand what a Lithium-ion Battery is, – AKA Li-ion battery or LIB – we need to understand how batteries work.
So, let’s get started!

At the core a battery is composed of 4 major elements:

• The cathode which is connected to the positive terminal.
• The anode which is connected to the negative terminal.
• The separator, situated between the electrodes preventing them from entering in contact while allowing ions to circulate freely.
• The electrolyte which is the medium that enable the ions to flow between both electrodes.

Basically, for LIBs, the cathode’s active material is composed of Lithium oxide, a conductive additive and a binder. Lithium oxide is the active material meaning that it is a chemical active component i.e. lithium ions. As you might have guessed the conducive additive increases conductivity and the binder well binds all together.

The anode is also composed of an active material - often graphite - which enables electric current to flow through an external circuit as well as emitting or absorbing lithium ions released from the cathode. In addition to the active material, usually, graphite is used as it has a very stable structure. Once again, a binder and a conductive additive are needed.

In the case of LIBs, the electrolyte is liquid and usually composed of materials with high ionic conductivity in order to allow lithium ions to move both ways. Therefore, the electrolyte is made of salts, solvents and additives.

How does it work?

When powering up a device – AKA discharging a battery – the lithium ions – in this case lithium which lost an electron – stored in the anode circulate through the electrolyte to the cathode where it is stored while the electrons – oh here it is – move along the electric wire and generate electricity.

Quite simple right, and guess what, for charging it’s the other way round.

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The Business Opportunities

Why do we use LIBs?

Since the rechargeable LIB was first commercialized in 1991 by Sony and Asahi Kasei, its adoption has reached records high! We use them in everything: phones, cars and even planes! But, why?

Well, one main reason is that it has twice the energy density nickel-based battery has, meaning it can store more. On the graphic below we can see the apparent advantage LIBs have on competition. If we take a look at phones, cars and other devices, weight is of utmost importance so the benefits are clear, for instance, a Tesla model 3 battery pack can store 150 Wh/Kg.

If you’re wondering what Lithium Polymer batteries are, I’ve decided not to talk about them in this article as to not make it unreadable, however if you are interested you can read about it here.

Another important factor is how well a LIB can hold its charge. Indeed, whereas a nickel-metal hybrid battery – AKA NiMH battery – loses 20% of its charge each month, LIBs manage to mitigate this to 5% . But NiMH batteries aren’t the only one suffering a crushing defeat, nickel-cadmium batteries – AKA NiCd batteries – have a disease: the memory effect meaning that they have to be discharged completely before recharging them if you don’t want to damage their durability, and guess what, LIBs couldn’t care less.

Oh yeah and it can also withstand hundreds of charge-discharge cycles.

Perfect right? Weeeeeeell, not exactly.

The issues with LIBs:

As soon as they are produced, LIBs will start degrading and usually, they last no more than 2 or 3 years whether you use them or not. And that’s if they’re not exposed to high temperatures, which would prove extremely harmful for the battery’s life expectancy. If we take a look at solar farms, this proves very problematic since temperatures tend to be extreme in these areas.

The cost is also problematic, today, LIBs are 40% more expensive to manufacture than NiCd batteries, an issue that Tesla and Panasonic are adamant on resolving thanks to the Gigafactory and mass production.

Another few minor issues worth mentioning are that once a LIB is completely discharged it can no longer be used, – don’t worry your phone will go to sleep to prevent that from happening – and that it requires a protection circuit so as to contain both voltage and current within safe limits.

Also, some may go KABOUM on you.

Concretely, what is happening in the world?

As you all know, Tesla has built its Gigafactory 1 where an expected 5 billion dollars will be invested by Tesla and its partners. The goal here is two-fold : create enough batteries for Tesla to be able to manufacture 500 000 cars per year and reduce the price of the electric vehicle battery pack by 30% by benefiting from mass production.

However, a change might be coming in the next years for LIBs as engineers are attempting to develop solid state LIBs i.e. where the electrolyte is no longer liquid. This could improve the storage capacity, the weight as well as security. Volkswagen has been investing in QuantumScape since 2012 and plans to add an extra 100 million dollars in order to develop a useable solid state LIB and plans to be able to manufacture it as soon as 2025.

In many aspects the technology has still room for improvement and companies such as Samsung are in an all-out race to deliver a fast-charging battery for mobile devices. By using graphene, Samsung hopes to improve its charging speed five-fold, – at the very least – in theory this would make it possible to reach a full charge in just under 12 minutes.

So, by the looks of it we’re going full LIB and even more so since no alternative for appliances and electric vehicles seems to be viable at this point in time.

Aaaand that's it for today!

Hope you've all enjoyed this Article, please leave a comment if you feel like it and an upvote if you like what you've felt! Resteems are also greatly appreciated!

I'll be releasing the next one in the series soon though I am not sure what it will be about.

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N°	Type	Source
1	Article	How LIBs work
2	Article	Volswagen
3	Article	Tesla Model 3
4	Article	Pros and Cons of LIBs
5	Article	Li-ion the ideal battery
6	Article	How batteries work
7	Article	Gigafactory 1
8	Article	Note 7 explosions
9	Article	Costs of bad manufacturing
10	Company site	Tesla Gigafactory 1
11	Company site	Samsung graphene battery

N°	Images
1	Modified image
2	Battery
3	LIB
4	Energy Density
5	Explosion
6	dollar

Fun Battery Fact:

After 140 confirmed cases of Note 7 overheating and catching fire, Samsung recalled the 2,5 million phones it had manufactured and provided 1,47 million replacements. This would have cost the company as much as 17 billion dollars.