The differences between solid-state vs. lithium-ion batteries are more pronounced in their real-world effects. Conventional lithium-ion batteries’ biggest advantage is their availability. These are the only market-viable EV batteries today, making others hard to justify on a large scale.
As research continues and manufacturing processes improve, solid-state batteries appear poised to become the preferred choice for EVs if the remaining challenges can be solved. However, for now, lithium-ion batteries remain the practical choice for most applications.
The key innovation in solid-state batteries is the use of solid electrolytes. Unlike Traditional lithium-ion batteries, solid-state batteries contain solid electrolyte materials. Solid electrolytes can be made from various materials, such as ceramics or polymers, that allow for the efficient flow of lithium ions while remaining in a solid state.
Schmuch et al. evaluate the cost of batteries with liquid electrolytes and graphite anode at about $58 per kWh. For solid-state batteries, they differentiate depending on the anode: with a 20% excess of lithium in the lithium metal anode, they calculate a price of about $75 per kWh; with a 300% excess, they determine a price of 128 kWh per kWh .
Solid-state batteries are more complex to manufacture compared to traditional lithium-ion batteries. The fabrication of solid electrolytes and ensuring good solid-solid interfaces between components require precise manufacturing processes. This complexity can currently make them more expensive to produce.
How much energy they can store: Solid state batteries can store more energy for their size and weight than lithium-ion batteries. Right now, lithium-ion batteries store between 250 to 300 units of energy (Wh/kg). Solid state batteries can store over 500 units. Cost: Solid state batteries are more expensive right now.