The key differences between solid and liquid lithium in batteries include their physical state, performance characteristics, safety profiles, and manufacturing processes.
What is a solid state battery?
The lithium-ion batteries that we rely on in our phones, laptops and electric cars have a liquid electrolyte, through which ions flow in one direction to charge the battery and the other direction when it is being drained. Solid-state batteries, as the name suggests, replace this liquid with a solid material.
A lithium-ion battery will typically have a graphite electrode, a metal oxide electrode and an electrolyte of lithium salt dissolved in some sort of solvent. In solid-state batteries, you might find one of a whole host of promising materials replacing the lithium, including ceramics and sulphides. Why is ditching a liquid electrolyte useful?
What is the difference between a lithium ion and a solid-state battery?
And while conventional lithium batteries quickly charge up to 80 per cent of their capacity, they charge slowly from there to 100 per cent. Solid-state batteries can be fully charged more quickly. Crucially, though, solid electrolytes are less dense, so a solid-state battery can be smaller and lighter than its lithium-ion competitor.
How does a solid state battery work?
Solid-state batteries can use metallic lithium for the anode and oxides or sulfides for the cathode, increasing energy density. The solid electrolyte acts as an ideal separator that allows only lithium ions to pass through.
Are solid-state batteries a viable alternative to liquid electrolyte Li-ion batteries?
For that reason, solid-state batteries can potentially solve many problems of currently used liquid electrolyte Li-ion batteries, such as flammability, limited voltage, unstable solid-electrolyte interface formation, poor cycling performance, and strength.
Improved safety: Solid-state batteries may eventually offer enhanced safety features compared to conventional Li-ion batteries. Non-flammable solid electrolytes, for example, are likely to reduce the risk of fire or explosion in the event of a crash, battery failure, or short circuit.