The Future of EV Batteries

What can we do to make electric car batteries (specifically Lithium-Ion) last longer on full charge and also improve lithium-ion batteries better in other ways.
Muhammad Hasan
Grade 6

Problem

The problem that I will be researching to solve in this project is to try to find a way to make EV batteries (in this project I will be focusing mainly on lithium-ion batteries) last longer on one charge so that we can increase the range for EV cars and improve in other ways such as battery life, energy density, and faster charging.

Method

  1. I got my inspiration by an idea that once came into my head. The idea was that you could attach a generator to the wheel of an electric car so that when the wheel turns, the car gets charged and it can last way longer then normal. It turned out that when I searched up if it was possible and my spirits were shoved down because the website I looked it up on (climatefeedback.org) said that it was not possible because "it cannot produce enough electrical energy to recharge the car's battery, based on the laws of physics. Furthermore, the generator uses energy from the wheel, making the car run slower and less efficiently." . Now that I couldn't do that as my science fair poject, I decided that I would do something else concerning electric cars and the first thing that I came across was the range issue.
  2. First I started researching about which rechargeable battery is the best and I found that it wast the lithium-ion battery. I started to do research on the lithium-ion battery like how it works and why it is better than other batteries. Next I researched what is a lithium-ion and what is electrolysis. After I finished all of my research and it was on my Google Doc, I made questions for interviews and looked up pictures that are relevent to my topic.
  3. Then I did more research about lithium-ion batteries and how they are better than other batteries. I also did more research on solid-state lithium-ion batteries and put all of my research on Microsoft Word.
  4. Now, I started my board, practiced my presentation, and researched for pictures that I can put on the board and use to explain how a lithium-ion battery works and about solid-state batteries.

Research

 

What is a Lithium-ion Battery?

According to UL Research Institute, a lithium-ion battery is the most common rechargeable battery that is used for electric cars and it is also the best one out in the market right now. A lithium-ion battery has 4 main parts: The positive current collector (can be the cathode or the anode), the negative current collector (can also be the cathode or the anode), the electrolyte, and the separator. When a lithium-ion battery is charging, the lithium-ions go from the cathode to the anode. When the battery is discharging the opposite happens and the lithium-ions go from anode to cathode.

What is a Lithium-Ion?

A lithium-ion is lithium (the element) that normally has 3 protons (positive), 3 electrons (negative), and 4 neutrons (neutral). According to study.com, an ion is a particle like an atom that has lost or gained electrons. So, a lithium-ion is lithium that used to have 3 protons and 3 electrons but lost one electron so now lithium does not have a neutral charge anymore thus making it a lithium-ion.

A Lithium-ion Batterie’s Parts, What They Are Made of, and Their Uses

Current Collector: According to MSE Supplies, the current collector can be made of copper, aluminum, nickel, titanium, stainless steel. The current collector's job is to make a bridge for the moving electrons from the active material to the outer battery terminals.

Cathode (positive electrode when discharging and negative electrode when charging): According to Aqua Metals, the cathode can be made of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, or lithium nickel cobalt manganese oxide. The cathode’s job is to facilitate the flow of the electric charge in the battery.

Anode (positive electrode when charging and negative electrode when discharging): According to targray.com, the anode is made of graphite coated on copper foil. The anode’s job is to release and to take in the electrons when the battery is charging or discharging.

(Liquid) electrolyte: According to Dragonfly Energy, the electrolyte is made of lithium hexafluorophosphate. The electrolyte’s job is to transfer the lithium-ions back and forth during charge and discharge.

Separator: According to Battery University, the separator is usually made up of polyolefin. The separator’s job is to make sure that the cathode and the anode do not physically meet because if they did meet it could cause a short circuit.

How Does a lithium-ion Battery Charge and Discharge?

According to Battery University, when a lithium-ion battery is discharging, the anode (negative electrode) faces oxidation or it loses electrons and the cathode (positive electrode) sees a reduction which is when it gains electrons. When a lithium-ion battery is charging, the reverse happens and the cathode (in this case negative electrode) faces oxidation and the anode (in this case positive electrode) sees a reduction where it gains electrons.

Possible Solutions for the Problem

The question is how can we make better lithium-ion batteries for electric cars so that they can last longer. A few possible answers to that question could be to just switch lithium-ion batteries to solid-state lithium-ion batteries which are almost the same things except solid-state lithium-ion batteries have a solid electrolyte (the thing that carries the lithium-ion back and forth between the cathode and the anode) which is safer because there is no chance of the electrolyte leaking and it has a higher energy density (holds more energy) than lithium-ion batteries with a liquid electrolyte.  Another way that we can make lithium-ion batteries last longer is by finding an alternative to the rare electrode materials that we use now because the electrode materials we use right now (metal oxides like cobalt, nickel, manganese, lithium, etc.) are rare and have a limited energy density so if we can find a good alternative with higher energy density that isn’t rare, it could make lithium-ion batteries last way longer on one charge. Another way we can make lithium-ion batteries better is by making them self healing so that they have a longer lifespan. We need self-healing lithium-ion batteries because the same electrochemical stuff that happens in a lithium-ion battery is also responsible for degrading the battery (making it go bad) so if you are going to use that battery a lot, then the battery is going to degrade at the same pace. (energy-storage.news)

The Best Solution

The best solution to the problem out of what I said would probably be to switch lithium-ion batteries to solid state lithium-ion batteries. A few reasons why this would be the best solution is because of a few reasons:

  1. Solid State lithium-ion batteries would have a longer lifespan. This is because solid state batteries have a solid electrolyte so even if the electrolyte breaks, it is still usable and thus you can use the same battery for 10-20 years while the normal lithium-ion battery only has a lifespan of only 2-3 years. (From LinkedIn.com)
  2. Solid State lithium-ion batteries have more energy density than normal lithium-ion batteries that have a liquid electrolyte. This means that solid state lithium-ion batteries hold more energy than normal lithium-ion batteries even if it is the same voltage. This is because solid state lithium-ion batteries have a solid electrolyte. (From LinkedIn.com)
  3. Solid State lithium-ion batteries have enhanced safety. This is because the solid electrolyte eliminates the risks associated with flammable liquid electrolytes, making them prone to overheating or fires. (From LinkedIn.com)

What is the Difference Between a Gas Car Battery and an EV Battery?

What Other Batteries Do EVs Use and Why Lithium-Ion Batteries Are Better Than the Others?

Some other batteries that EVs use include Lead Acid, Ultracapacitors, Lithium Iron Phosphate, Nickel-Cadmium Batteries . (afdc.energy.gov)

 

Lead Acid Batteries: According to Battery Accessories, a lead acid battery is a rechargeable battery that uses lead and sulphuric acid to function. How it works is that the lead is submerged into the sulphuric acid which allows a controlled chemical reaction. This chemical reaction is what is used to generate electricity. To recharge a Lead Acid battery, all you have to do is reverse the reaction.

 

Ultracapacitors: According to Aptiv.com, Ultracapacitors are not batteries but they are able to collect and store electricity very effectively. Ultracapacitors also store and release electricity faster than a battery.

 

Nickel-Cadmium: According to Science Direct, a nickel cadmium battery is a rechargeable battery works in kind of the same way as lithium-ion batteries which work by the movement of ions between the electrodes which creates free electrons (A.K.A. Electrolysis).

Lithium-Iron Phosphate: According to First Phosphate, a lithium-iron phosphate battery is a rechargeable battery also operates using electrolysis where the phosphate moves between the two electrodes.

Pros and Cons of a Lithium-Ion Battery

Pros of lithium-ion batteries (according to selex.vn):

  1. Lithium-ion batteries have a long lifespan. Lithium-ion batteries can be used for about 2000 charge and discharge cycles, giving a longer battery life from 8-10 years.
  2. Lithium-ion batteries have a high energy density (hold more energy) than most other rechargeable batteries
  3. Lithium-ion batteries have enhanced safety. Since manufacturers have to meet certain safety standards, they are resistant to water, explosions, and other hazards
  4. Lithium-ion batteries have faster charging times compared to most other batteries.

 

Cons of Lithium-ion batteries:

  1. Lithium-ion batteries have a higher cost compared to most other batteries
  2. Lithium-ion batteries are not that easy to repair and maintain
  3. even though lithium-ion batteries are mostly safe, they still have some safety issues that have not been solved yet.

Why Do Electric Car Companies Not Use Solid-State Lithium-Ion Batteries if They Have a Higher energy Density?

According to DW.com, the main reason why EV companies do not use solid-state lithium-ion batteries is because they are more expensive due to a higher amount of lithium in the batteries.

Data

Battery:

Lithium-Ion

Lead Acid

Ultracapacitors

Nickel-Cadmium

Lithium-Iron Phosphate

Solid-State Lithium-Ion

Battery Life:

5 years

3-5 years

3+ years

8-10 years

5-10 years

10-15 years

Charging Time:

2-3 hours

8 hours

10-12 hours

14 hours

5 hours

6.5 hours

Energy Density:

(Wh/kg)

200-300

Wh/kg

35-40 Wh/kg

206

Wh/kg

50-80

Wh/kg

125

Wh/kg

1440

Wh/kg

Overcharge Tolerance:

Low

High

Not Subject to Overcharge

Moderate

Low

Moderate

Conclusion

EV batteries need longer range and need to become better in other ways. The lithium-ion battery solves most of these problems but it still has some cons like high cost, hard repair, and some safety issues. In this project I researced on how we can make lithium-ion batteries last longer on one charge and to make them better in other ways like longer battery life and lower cost. The main solution that I stated in this project was to make lithium-ion batteries solid-state because it increases battery life and has higher energy density. Solid- state lithium-ion batteries are better than other batteries because of reasons like higher energy density and slow degradation. By the end of my project, you should be able to understand how rechargeable batteries like lithium-ion work and how we can make them better.

Acknowledgement

I would like to acknowledge my teacher, my science fair coordinator, and my mom for all helping me with this project a lot (especially my mom)