Revolutionizing Energy: Cleaner and Cheaper Batteries on the Horizon

Why More Batteries?

It is vital for our society to substantially decrease the use of fossil fuels to harvest energy and the path forward is batteries. In the process of combustion, fossil fuels like coal, oil, and natural gasses are burned. Energy released by the process of burning is converted into electricity via turbines. When fossil fuels are burned, vast amounts of CO2 are released into the atmosphere, creating a heat-trapping blanket around our Earth. This leads to the phenomenon we experience called climate change or global warming. In order to prevent the progress of climate change is crucial to further develop renewable energy sources, like solar energy or that from windmills.

For instance, a factory owner would view fossil fuels favorably for energy due to their reliability and accessibility at any time. The operation of the factory is not reliant on the amount of sunlight available or the speed of the wind. Batteries play a critical role in decarbonization by allowing the storage of renewable energy sources such as solar and wind, elevating the efficiency of these methods. With the introduction of electric cars, batteries reduce the dependence on internal combustion engines, helping decrease carbon emissions from the transportation sector​. If global warming is to be prevented, then renewable energy must be used, and if renewables are to become widespread, then we must boost battery production. Now the question is this: how do we make batteries more high-capacity and use resources wisely.

How Do Lithium Batteries Work?

A lithium battery has 2 main parts called electrodes. The positive electrode is called the cathode and the negative electrode is called the anode. Between these electrodes is a special liquid or gel called the electrolyte that allows lithium ions to move between the electrodes. These batteries also have thin separators to keep the electrodes from touching each other and still allowing the lithium ions to pass through. When the battery is charged, lithium ions are pushed from the positive electrode through the electrolyte and to the negative electrode where they are stored. During usage, the lithium ions go back to the cathode and as the ions move through the device, the flow of electrons provides it with power?

The Issue

Extracting lithium is damaging to our environment because of chemicals used to break down mining ore. Industrial acids used for this purpose include hydrochloric acid, and sulfuric acid, and sodium carbonate. If these chemicals leach into groundwater and surface water, it can harm aquatic ecosystems. Additionally, such chemicals can also alter soil chemistry, by disturbing normal pH levels and inhibit plants' growth in the area. Because of this, the LESC performed research to create anode-free sodium solid-state batteries that are faster and safer for the environment. Lets break it down.

Why Sodium Batteries?

The difference between a lithium battery and a sodium battery is that a sodium battery uses sodium ions and a lithium battery uses lithium ions. Lithium is not as common as opposed to sodium. It comprises of about 20 parts per million of the Earth's crust. In comparison, sodium is 20,000 parts per million. The abundance of sodium makes its use in batteries a favorable option because there is less supply of lithium. Plus, of course, sodium mining is less resource intensive and requires less hazardous chemicals than lithium mining.

Why Solid-State Batteries?

Solid-state batteries use a solid electrolyte instead of a liquid one. Liquid electrolytes used in lithium batteries can leak and are flammable. A solid electrolyte reduces that risk factor. Meaning, they can store more energy in the same amount of space, leading to longer-lasting batteries for devices and electric vehicles. Furthermore, solid electrolytes allow for tighter packing of the battery cells, increasing the overall energy density. This means more energy can be stored in the same amount of space, resulting in longer-lasting batteries for devices and vehicles​.

Why Anode-Free Batteries?

Anode-free batteries, as the name suggests, are without the anode electrode. When the battery is charged, lithium ions move from the cathode through the electrolyte and deposit as lithium metal directly onto the current collector, which then functions as the anode during discharge. This design allows for increased energy density because more substance is packed into the same volume battery. Also, eliminating the anode reduces the need for mining and processing materials like graphite, thus being a more eco-friendly option.

LESC's Innovation

LESC, for the first time, combined and executed the three ideas of solid-state electrolytes, sodium ions, and anode-free in one battery. In a anode-free battery it is critical that the electrolyte is in close contact with the current collector which is easy when the electrolyte is a flowy liquid. To tackle this problem, the team came up with the innovative idea of creating a current collector that surrounds the electrolyte instead of an electrolyte that surrounds the current collector. The current collector was made out of aluminum powder which is a solid that can also flow like a liquid. The powder was put under high pressure to densify the current collector while still having liquid-like contact with the electrolyte. At mass, these novel clean batteries could help push forward the use of renewable energy in the face of climate change