Written by Cameron DeWith
Electric vehicles have made a bold entrance into the auto industry through their success in the global market. However, electric vehicles have failed, as of yet, to make gasoline-powered cars entirely obsolete; the range of a battery on a single charge has not yet reached the range of a gasoline-powered engine on a single tank of gas. Solid state batteries, an emerging technology, have the potential to reach and surpass this threshold.
How They Work
In order to understand how a solid state battery works, it is important to first understand how every battery works. In every battery, there are two electrodes: a negative anode and a positive cathode. An electrolyte exists in between these electrodes. Positively charged ions travel through the electrolyte to the cathode to free electrons in the anode. These electrons are attracted to the cathode, but the electrolyte stops the flow of electrons to the cathode. Instead of travelling through the electrolyte, the electrons run through a circuit to the cathode, generating electricity. Batteries recharge through a reverse of this process.
What makes solid state batteries different from other batteries? Solid state batteries use a solid electrolyte instead of a liquid electrolyte. This comes with a host of benefits. To understand how solid state batteries could change the auto industry, I will explore the advantages and disadvantages of solid state batteries compared to lithium-ion batteries, the current norm in electric vehicles.
Solid state batteries possess many advantages over lithium-ion batteries.
- The solid electrolyte in solid state batteries is smaller in size than the liquid electrolyte in lithium-ion batteries. This allows solid state batteries to be more energy-dense than lithium-ion batteries; small solid state batteries offer the same output of power as larger lithium-ion batteries. This provides the opportunity for more batteries to be used in the same fixed space. In vehicles, the space for a higher quantity of batteries would permit higher power and longer range.
- Solid state batteries are safer than lithium-ion batteries. Exothermic reactions, reactions that release energy, occur within lithium-ion batteries and cause heat. This heat has the potential to cause a battery to expand and rupture, releasing a flammable liquid electrolyte. This process has caused minor explosions. The solid electrolyte found in solid state batteries eliminates this problem because there is no flammable liquid electrolyte.
- Solid state batteries can be charged more times than lithium-ion batteries. In lithium-ion batteries, the liquid electrolyte hinders battery life by slowly corroding the electrodes in the battery. However, the solid electrolyte in solid state batteries does not corrode the electrodes. A solid electrolyte would allow batteries to last roughly five times as long as current batteries.
Solid state batteries have a couple of disadvantages when compared to lithium-ion batteries.
- Manufacturing solid state batteries at a large scale is difficult. This is likely due in large part to the newness of the technology and the complexity of going from lab knowledge to mass production.
- The perfect material for a solid electrolyte with the ideal ionic conductivity has yet to be found.
Solid state batteries seem to offer great potential for the future because of the many advantages they possess over their lithium-ion counterparts. However, this technology will not likely be available until at least 2025. In his review of current lithium-ion batteries and future solid state batteries, Andrew Ulvestad found that “the current lithium-ion battery paradigm will likely continue for the foreseeable future” because of “the technical challenges with solid state electrolytes coupled with the rapidly decreasing cost of liquid electrolyte lithium ion batteries” (2018, p. 12). It might be a little while before you are able to purchase your electric vehicle with a solid state battery.
I have always been entranced by electric vehicles and the opportunities they provide for a more sustainable world. The newness of the technology and the range limitations have always made me curious about future electric battery technology and its potential impacts. Solid state batteries are one such future electric battery technology that, when it comes, will completely change the auto industry. I am extremely excited for the day when electric vehicles are able to outperform gasoline-powered vehicles in range; combustion engines will become obsolete and humanity will be less reliant on fossil fuels. Perhaps the solid state battery will be the technology to finally take us there.