Spark plasma sintering (SPS) consolidates powders to near-theoretical density in minutes rather than hours, using pulsed DC current and uniaxial pressure to drive Joule heating directly through a graphite die. The short dwell time and high heating rate suppress grain growth, preserve metastable phases, and let researchers densify materials that decompose, lose lithium, or coarsen under conventional pressureless sintering. For solid-state battery, thermoelectric, and ceramic-electrolyte work, SPS is the densification step that lets you study the bulk transport properties of a material rather than the porosity between its grains.
Equipment in this collection covers the full SPS workflow:
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SPS furnace systems — pulsed DC power supplies coupled with hydraulic uniaxial pressing, vacuum or inert-atmosphere chambers, and pyrometer or thermocouple temperature feedback for closed-loop ramp control.
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Graphite dies, punches, and spacers — consumables sized for standard pellet diameters, used to confine the powder and conduct current and pressure into the green body.
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Graphite foil and felt liners — placed between powder and tooling to prevent sticking, smooth current distribution, and protect the die wall from reactive ceramics.
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Vacuum and inert-gas accessories — pumps, gas lines, and feedthroughs that keep oxygen and moisture out of the chamber during densification of oxide and sulfide electrolytes.
SPS is particularly useful for garnet-type LLZO, NASICON-type LATP and LAGP, sulfide electrolytes such as Li6PS5Cl and Li10GeP2S12, and dense oxide cathodes for thin pellet test cells. Because heating goes through the sample itself, ramp rates of hundreds of degrees per minute are routine, which matters when the target phase is only stable in a narrow window or when lithium loss must be limited.
If you are densifying solid electrolytes for impedance and DC polarization measurements, start here and then see Solid-State Synthesis for upstream calcination and milling steps. For follow-on cell assembly, see Coin Cell Assembly; for pressing-only consolidation without the pulsed-current step, see Hydraulic Presses.
