What if EV batteries could charge faster and last longer?

Created By RISC | 2 years ago

Last modified date : 2 years ago

Electric vehicles (EVs) are becoming more popular. They can be seen in adverts and on the street as gasoline prices soar and people care more aware about the environment. ​

But electric vehicles still have downsides. Short range, long charging times, and low battery capacity are common fears. But could batteries be developed soon to overcome such constraints? ​

Lithium-ion (Li-Ion) is the most common type of electric car battery: ​
• Electrodes are separated into cathode (positive) electrodes, which are usually made of lithium metal: LiMO₂, LiM₂O₄, and anode (negative) electrodes, which are usually made of lithium metal: LiMO₂, LiM₂O₄. ​
• The cathode is separated from the anode by a separator, which avoids a short circuit. ​
• Electrolyte solution: a solvent-based solution of lithium salts like LiPF₆ or LiBF₄ acts as an electrical conductor for lithium ions (Li⁺) but not electrons. ​
• Current collector: a metal conductor that allows electrons to pass via an external circuit and generate electricity. ​

Electrochemical principles govern the operation of lithium-ion batteries. When charged Li⁺ moves from the cathode to the anode through the electrolyte solution, it stores an electric charge. The Li⁺ accumulated at the anode flows back to the cathode while running (discharging) the battery, passing through the current collector to be turned into electrical energy until the chemical process ends, or until the battery runs out. The battery must be recharged before it can be used again. Lithium-ion batteries have a finite lifespan of about 500 charge cycles. The electrolyte solution is also flammable, which could result in a fire if it overheats. ​

These restrictions mean Lithium-ion batteries take a long time to charge and can only store a limited amount of electricity. So electric automobiles can only run for a short time before needing to be recharged. Efficiency can be improved, however, by including graphene as a component. ​

Graphene's exceptional electrical conductivity and electronic characteristics mean a "graphene battery" has been built with graphene as the cathode, improving performance: ​
• Faster charging time ​
• Higher battery energy density
• Longer-lasting energy storage even at low temperatures so the battery can work normally without discharging ​
• Less heat generated than with lithium-ion batteries during charging

Real Graphene, a US graphene battery company, has succeeded in manufacturing batteries with fast charging and high capacity. They take only 20 minutes to charge from 0% to 100%, compared to 90 minutes with lithium-ion batteries. They also last for 1,500 charge cycles and are safe to use while charging because they emit less heat. ​

Story by Supunnapang Raksawong, Materials Researcher, RISC

References: https://properea.com/graphene-batteries-18-03-2022/