There is widespread belief in the industry that the tipping point for mass EV adoption and therefore scale up the production of EV’s will come at the point the price of a battery cell hits $100 /kWh. We have already seen the price come down from $1000 /kWh to somewhere around $200 /kWh in 2018. However to see real scale, electric vehicles need to become more affordable which is why that $100 mark is so important. Are solid state batteries the answer to help get us to the magic number?
3 key things to know about the battery:
Energy Density This refers to the capacity of a battery. A Nissan 22 /kWh battery means it can store 22 /kWh of power. The higher the energy density, the longer the battery stays charged = longer range
Power Density This refers to the how fast a battery can charger and discharger power. The higher the power density = the faster the car will charge. The limit on power density is the reason why you cannot charge a Nissan Leaf any faster on a 100kw chargers vs 50kw chargers
Battery Composition The battery is made up of a collection of modules. Each module is made up of a collection of cells. Therefore the more cells that you can fit into a module and the more modules that you can fit into a battery, the higher then storage capacity of the battery and therefore the more range you can travel!
What are the key problems with Batteries today?
Rapid charging causes battery degradation. Although there are calls to increase rapid charging infrastructure, constantly rapid charging will degrade the battery. This is a problem today since any degradation on low energy density batteries make a big impact on the range. For future batteries with higher capacity (40kWh +), this may not be such a big issue.
Extreme temperatures (cold or hot) will increase the degradation of the battery. Therefore the quality of the battery over a period of time will be influenced by the location of the EV. (E.g. an EV battery in the Sub-Saharan Africa will degrade much more than an EV battery in the UK).
Batteries today are highly dependant on Cobalt. Batteries use 3 main raw materials: Nickel, Magnesium & Cobalt. Cobalt is the biggest problem since it is rare and expensive. Future developments will need to reduce the dependency on Cobalt to bring down price.
Batteries need to become cheaper, pack more density, become safer and reduce dependency on Cobalt. The cost of a today is approximately $250 /kWh, the aim is get to $100 /kWh.
However it is believed the current lithium-ion battery technology has reached it’s potential in terms technological efficiency and therefore economic efficiency.
What is a Solid State Battery?
Solid-state batteries replace the liquid or polymer electrolyte found in current lithium-ion batteries with a solid material, therefore requiring less space.This means solid state batteries can pack more density and aren’t as bulky. The solid state battery still works in the same way a lithium-ion would work but the change in materials bring many benefits.
Current lithium-ion battery technology has reached it’s potential in terms technological efficiency and therefore economic efficiency.
Benefit of a Solid State Battery?
Increased density means they carry more power, which means longer range vehicles. They can pack up to twice as much energy as lithium ion batteries.
Solid state electrolytes are less reactive than liquid/gel electrolytes found in lithium -ion and therefore they are less prone to degradation and will last longer.
Solid state batteries are much safer for the same reason as above.
Whether we can get to the $100 barrier using Lithium - ion battery technology or not is to be seen. However, the breakthrough of solid state batteries to go beyond R&D and into production will be a real tipping point for mass market production and take up of electric vehicles.
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