Making Solid-State Battery Electrodes That Don't Swell and Crack

This patent describes a special design for solid-state battery electrodes that uses tiny internal holes and spaces between particles to prevent them from expanding and cracking during charging and discharging.

What it covers

This patent describes a composite electrode for all-solid-state batteries, which are a new type of battery that uses solid materials instead of liquids. The electrode is made of "solid-state electroactive material particles" that change size when the battery charges and discharges, and "solid-state electrolyte particles" mixed in (Claim 1). The clever part is that each electroactive particle has "internal pores formed therein," like tiny sponges. There are also spaces, called "interparticle porosity," between the electroactive and electrolyte particles (Claim 1). These internal pores and interparticle spaces work together to absorb the expansion and contraction of the electroactive material, preventing the electrode from swelling outwards, cracking, or falling apart (Abstract, Claim 1). For example, an electrode might use silicon particles with 10% to 75% internal porosity, mixed with solid electrolyte particles, leaving 5% to 40% space between them (Claim 2, Abstract).

What it doesn't cover

• —Does not cover electrodes for traditional lithium-ion batteries that use liquid electrolytes.
• —Does not cover solid-state electrodes that lack both internal pores within the electroactive particles and interparticle porosity between the electroactive and electrolyte particles.
• —Does not cover electrodes where the electroactive material is a solid block without a network of internal pores.
• —Does not cover battery chemistries that do not cycle lithium ions, as the patent specifically mentions "cycles lithium ions" (Claim 1).
• —Does not cover electrodes where the solid-state electroactive material and solid-state electrolyte are not in particle form and intermingled.

The clever bit

The truly novel aspect is the dual-level porosity: internal pores within each electroactive particle and additional spaces between these particles and the solid electrolyte. This allows the electroactive material to expand inwards into its own pores, while the interparticle spaces further buffer any remaining outward expansion, preventing overall electrode damage.

Why it matters

Solid-state batteries promise safer, higher-energy-density power for electric vehicles and portable electronics. However, a major challenge is that electrode materials expand and contract significantly during use, which can damage the battery and shorten its life. This patent from GM addresses this critical problem by designing electrodes that can withstand these volumetric changes, potentially making solid-state batteries more durable and reliable for widespread adoption.

Real-world examples

• 1.Future electric vehicle batteries
• 2.High-performance portable electronics
• 3.Grid-scale energy storage systems
• 4.Aerospace and defense applications requiring high energy density