What are the components of an electric vehicle battery?
Electric vehicle batteries have been called the “heart” of EVs. Much like the vital organ of the human body, it distributes electrical power to the various systems of an electric car. It also has the capability of storing energy for your next drive.
EV batteries are just as complex as the human heart. You cannot just define EV battery components as the physical parts of the battery. Perhaps, even more important are the chemical compositions of these components, the reactions of which generate electrical energy.
In this article, we shall take a much closer look at the vital components of an electrical vehicle battery.
What are EV batteries made of?
What are EV batteries made of? When you talk about EV battery components, what is being discussed are both the chemical composition and physical parts that comprise EV battery cells. These cells, in turn, are combined into modules which are then assembled into EV battery packs. But let us focus on the individual cells of EV batteries, particularly on lithium ion EV batteries which are the most common battery types today.
An EV battery has four major components: the positive electrode called the cathode, the negative electrode called the anode, a micro-permeable separator which keeps these two electrodes apart, and an electrolyte (a lithium salt solution called lithium hexafluorophosphate). The cathode is made out of lithium, manganese, nickel, and cobalt. The anode is commonly made out of graphite but, like the cathode, it also contains lithium.
When discharging EV batteries while driving, electrical power is generated by the flow of lithium ions from the cathode to the anode. The reverse happens during battery charging wherein lithium ions flow from the anode to the cathode, so that the electrical energy gets stored.
How long does an ev battery last?
How long does an EV battery last? The average EV battery lifespan is between 10 and 20 years, although the longevity of EV batteries can be improved through proper care and usage of both the vehicle and the battery.
Expect degradation of the battery to occur with time and aging, storing your vehicle in extreme temperatures, and frequent use of direct chargers.
How are EV batteries manufactured?
Manufacturing EV batteries is a complex and intensive process that requires intricate assembly and strict testing and quality control. The first to be manufactured are the individual cells of the electric vehicle batteries, in the layout mentioned above. These components are then encased in a metal housing. Tests are conducted on each cell to detect electrolyte leaks and internal moisture seepage.
Depending upon the model of the EV, these EV batteries are combined in another housing to form modules. The module housing protects the cells from external vibrations and shocks. Finally, these modules are assembled into battery packs, which are then installed into the electric vehicle.
Let’s take a look at the Nissan Leaf as an example. The first Nissan Leaf model has four cells inside a module. 48 modules make up the battery pack of this EV. This means the Nissan Leaf has 192 individual battery cells with a 24 kWh capacity.
How much does an EV battery cost?
According to EVBox.com, it is estimated that the majority of EV batteries have a lifespan of 10-20 years, after which they will need to be replaced. Of great concern among vehicle owners is the cost of the electric vehicle battery itself, which is considered to be the most expensive part of an EV. In the past, the EV battery packs used to have an average cost of $5,000, with certain car models having EV batteries costing as much as $15,000.
Thankfully, a dramatic reduction in EV battery cost has been observed during the past decade. At present, the average price of a kilowatt-hour (kWH) – the standard measure of EV battery price – has dropped from $1,160 per kWh in 2010 to $128 per kWh. It is projected that the price will drop even further, stabilizing at $90 per kWh by 2031.
Are EV batteries sustainable?
There is the question on whether EV batteries are sustainable or not. Sustainable EV batteries are largely dependent upon their chemical compositions, especially the valuable metals found in the cathode. According to the U.S. Geological Survey, the global reserves of lithium is presently at 21 million tonnes.
However, there are potential shortages for nickel and cobalt, which is primarily sourced from the mines of the Democratic Republic of Congo. There are also concerns about the toxicity of cobalt and the detrimental effects it has on the health of miners, including child workers.
Future EV battery technology hopes to eliminate nickel and cobalt from the cathode. One proposed method is using small amounts of other metals while retaining the lithium cobalt oxide crystal structure of the cathode.
Another proposed approach is the use of disordered lithium-rich rock salts which allows for the easy flow of ions between the cathode and anode, but requires a more abundant metal (manganese) to stabilize the reaction instead of nickel or cadmium.
Are EV batteries safe?
EV battery design – starting from the EV battery components to the battery packs themselves – seeks to ensure safety. While electric vehicle batteries are relatively safe, there have been reports of batteries catching fire.
EV batteries have the potential of being fire hazards because of the use of electrolytes that are volatile and highly flammable when subjected to high temperatures. For this reason, EV batteries come with an active cooling system to prevent overheating and fire.
Another potential source for fire is damage to the separator. If the separator breaks in an accident, it can cause physical contact between the cathode and anode, resulting in a short circuit. The cathode ends up undergoing rapid discharge which overheats the electrolyte, leading to a fire.
EV battery research is looking into the development of solid-state batteries which eliminates the use of flammable liquid electrolytes and which can endure high temperatures. Elimination of cobalt also improves the stability of the battery, so that there is lesser potential for fire.
Last but not least, blade batteries are being produced which contain lithium-iron phosphate blocks for the cathodes. These batteries are much cheaper than the current lithium-ion varieties and are less prone to overheating.
EV battery components are not only vital for the proper functioning and energy distribution in an electric vehicle. With the right components, safety while driving can be assured. However, researchers are presently looking into readily able chemical/metal components that will not impact on the environment and human health. In fact, EV batteries should not be disposed of in the global waste stream to avoid adverse effects to the ecosystem and health. They can either be reused for other purposes with less energy demands or recycled through chemical processes.