Well, why this topic? You see, the age of V8, V6, turbocharged, and naturally aspirated is now being slowly replaced with hybrid and electric. You may be familiar with the intake, compression, power and exhaust terminologies of our ongoing combustion engines, but it is time we also get aware of the terminologies of battery tech like - Mass energy density, Volume energy density, power density, charge-discharge efficiency and so on. Well, we will not get into how a battery works, but we will throw light on the different types of batteries and their chemistry being used on our electric vehicles and how one is different from one other.
Let's start with one of the most common battery types that get used in our electric vehicles- Lithium Ion.
Because lithium is one of the most electropositive elements in our periodic table, that can be extracted and put to good use-case. Now, what's electropositivity? Well, electropositivity is nothing but a measure of how easily- an element can donate its electrons to produce positive ions. In a battery, the cathode is a negative electrode, an anode is a positive electrode, and there is an electrolyte which separates them, creating a proper electrochemical potential to get it functional. And lithium-ion batteries differ based on the lithium compound used in electrodes.
First, let's talk about LFP batteries, also known as Lithium Ferrous Phosphate, which are commonly used in electric cars like the Tata Nexon EV. Also, Tesla moved to LFP chemistry from nickel-cobalt-aluminium. This chemistry is widely popular and being put to use because of its high thermal stability and wide operating range. And it also has a more efficient charging and discharging cycle.
Lithium Cobalt Oxide (LCO)
This is also a well-known lithium-ion battery consisting of a cobalt oxide cathode and a graphite carbon anode. Well, according to research- it has high energy density but has a significantly low specific power, and comparatively low thermal stability, thus making it a bit of a fit for electric vehicles.So, you find this chemistry in laptops and smartphones.
And also, according to the USD Department of Energy- Cobalt is considered the highest material supply chain risk for electric vehicles (EVs) in the short and medium term.
Lithium Manganese Oxide (LMO)
This battery uses Lithium Manganese Oxide as the cathode and forms a 3-dimensional spinel structure, thus resulting in better ion flow with minimal internal resistance. Thus, this setup also improves thermal stability and better current flow.
Well, with the blending battery chemistry improving, manufacturers worked on the combination of LMO-NMC chemistry, wherein LMO delivers high current acceleration, whereas NMC provides good efficiency for a more extended driving range. Ex- BMW ix and Nissan leaf.
NMC battery ( Lithium Nickel Manganese Cobalt Oxide )
One of the popular chemistry in lithium-ion batteries is wherein - the cathode combination is typically one-third nickel, one-third manganese and one-third cobalt. Well, sometimes you see the battery written as NMC 532 , which generally resembles the 5 parts nickel, 3 parts cobalt and 2 parts manganese.
Mahindra XUV400 uses this chemistry in its battery pack. It's surely a bit old technology. It has its own pros and cons, and we will throw more light on this technology and explain its use case later.
NCA ( Lithium Nickel Cobalt Aluminium )
Lithium nickel cobalt aluminium oxide battery is an emerging battery technology with high specific power and better efficiency. It is similar to NMC, with manganese material swapped with aluminium, which improves the battery's lifespan. Tesla has explored the capabilities of using this chemistry for their electric vehicles.
LTO (Lithium-Titanium Oxide)
This updated lithium-ion battery uses titanate instead of carbon on the anode, thus giving more surface area and helping to charge faster, but it has lower energy density.
Startups like Log9 are exploring the potential of this chemistry. That being said, development in chemistry is taking rapid growth, and what is relevant today might not be tomorrow. Manufacturers and scientists are in a better search to replace lithium with other elements, and constant innovations are going on to make all things sustainable.