The Future of Solid-State Batteries

Credit: Forbes

Introduction

All-Solid-State Battery is a type of battery that uses no liquid electrolyte, instead, it uses a solid electrolyte (alternative to the lithium-ion battery). This type of battery still has not been commercially used, but will soon be used in electric vehicles. The demand for the production of solid-state batteries is due to the advantages that arise from the safety issue. Solid electrolytes are solid that exhibit ionic conductivities of about 10−3 S/cm, and it conducts ions between the cathode and anode in the lithium-ion battery.

What is Solid-State Battery?

A solid-state battery has a higher energy density than a Lithium-ion battery that uses a liquid electrolyte solution. It doesn’t have a risk of explosion or fire, so there is no need to have components for safety, thus saving more space. Then we have more space to put more active materials which increases battery capacity in the battery. A solid-state battery can increase energy density per unit area since only a small number of batteries are needed. For that reason, a solid-state battery is perfect to make an Electric Vehicle (EV) battery system of module and pack, which needs high
capacity. Despite improvements in technology over the last decade, issues such as long charging times and weak energy density persist.

What is Lithium-ion Battery?

Lithium Battery uses an intercalated (Intercalation is the reversible inclusion or insertion of a molecule into materials with layered structures) lithium compound as one electrode material, compared to the metallic lithium used in a non-rechargeable lithium battery. The battery consists of electrolyte, which allows for ionic movement, and the two electrodes are the constituent components of a lithium-ion battery cell. Lithium ions move from the negative electrode to the positive electrode during discharge and back when charging.

Advantages of Solid-State Battery

The advantages of the solid-state battery technology include higher cell energy density (by eliminating the carbon anode), lower charge time (by eliminating the need to have lithium diffuse into the carbon particles in conventional lithium-ion cells), ability to undertake more charging cycles, and thereby a longer life, and improved safety. Lower cost could be a game-changer, given that at 30% of the total cost, battery expenses are a key driver of vehicle costs.

R&D in Solid-State Battery

Most companies hope to commercialize their solid-state batteries by 2025, although small-scale production may happen earlier. However, to meet this goal, considerable R&D needs to happen to solve serious issues about material behavior, battery microstructure, charge longevity, and cracking upon thermal expansion and contraction. In another recent development, researchers from Brown University have developed a new material for use in solid-state batteries that is derived from trees. The solid ion conductor combines copper with cellulose nanofibrils—polymer tubes derived from wood. The paper-thin material has an ion conductivity that is up to 100 times better than other polymer ion conductors, making it a possible candidate for a solid battery electrolyte or as an ion-conducting binder for the cathode of an all-solid-state battery.
 

Conclusion

Today’s state-of-the-art batteries—those based on lithium-ion technology—have been honed to near perfection since they were introduced more than 25 years ago, but they are still heavy and occasionally explode and catch fire, as they did in Samsung’s Galaxy Note 7 phones so spectacularly last year. By getting flammable liquid electrolytes out of lithium-ion batteries and replacing them with solid electrolytes, solid-state battery makers hope to usher in an era of safer, more compact, higher-capacity energy storage devices.

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