Solid-State Batteries Have Significant Advantages, Many Parties Vying for First Layout
As a representative of clean energy, lithium-ion batteries, due to their high specific energy/power, environmental friendliness, and long service life, have become one of the most competitive electrochemical energy storage devices. Currently, lithium-ion batteries have been widely used in portable electronics and electric vehicles. However, the energy density of traditional lithium-ion batteries with graphite negative electrodes is approaching its theoretical limit based on oxide cathodes.
With an organic liquid electrolyte, lithium-ion batteries inevitably undergo side reactions during charge and discharge. Electrolyte volatilization and leakage during cycling lead to irreversible capacity loss, affecting lithium-ion battery life. Additionally, safety concerns from flammable organic electrolytes have sparked public worries about lithium-ion battery safety, especially in key industries like aerospace, electric vehicles, and grid storage where battery safety is paramount.
Solid-state batteries using solid electrolytes instead of liquid organics are expected to solve traditional lithium-ion battery challenges like energy density, cycle life, and safety simultaneously. This aligns with future high-capacity secondary battery development directions and is an ideal power source for electric vehicles and large-scale energy storage.
Solid-State Batteries – Next Generation High-Performance Batteries
Solid electrolytes, also known as fast ion conductors, have been theoretically researched since the 1972 NATO conference on “Fast Ion Transport in Solids” in Belgirate where Steele discussed solid electrolyte fundamentals. That year, Armand applied solid β-alumina as the electrolyte in a Li/TiS2 battery. In 1978, Armand conceptualized groundbreaking polymer solid-state batteries, after which solid-state battery development proliferated.
Compared to liquid electrolytes, solid electrolytes lack fluidity, leading to poor direct solid-solid contact and interfacial challenges due to electrochemical instability. However, versus liquid batteries, solid-state batteries offer potential advantages like:
- High safety from non-volatile, non-flammable solid electrolytes versus organic options.
- Good temperature adaptability for wider operating ranges, especially at higher temperatures.
- High energy density by enabling lithium metal anodes while improving on graphite/silicon-carbon negative electrodes.
- Simplified cell, module, and system designs by eliminating fluid electrolyte flow constraints.