Micromachined electrolyte sheet

1. A process for forming a ceramic lithium-ion electrolyte membrane, said process comprising the steps of:

fabricating a fired lithium-ion electrolyte sheet, wherein the step of fabricating a lithium-ion electrolyte sheet comprises the steps of

mixing starting materials,

treating the mixed starting materials to form a lithium metal phosphate powder,

further processing the powder to a particle size of less than about 5.0 μm,

adding phosphoric acid to the powder, wherein adding phosphoric acid to the powder comprises adding to the powder P 2 O 5 in the range of 0.5 to 5 wt % of an inorganic solids content of the powder,

casting the powder to form a tape, and

firing the tape;

and subsequently

cutting at least one edge of the fired tape with an ablative laser to form an ablative edge.

2. The process of claim 1 , wherein the ablative laser comprises an Nd:YVO 4 laser.

3. The process of claim 1 , wherein the ablative laser has a wavelength of less than about 2 μm, a fluence of less than about 250 Joules/cm 2 , repetition rate between about 20 Hz and 100 MHz, and cutting speed over about 10 mm/sec.

4. The process of claim 1 , wherein the ceramic lithium-ion electrolyte membrane is less than about 200 μm thick.

5. The process of claim 1 , wherein the ceramic lithium-ion electrolyte membrane is comprised of grains having an average grain size of less than about 5 μm.

6. The process of claim 1 , wherein the ceramic lithium-ion electrolyte membrane has a relative density greater than about 90%.

7. The process of claim 1 , wherein the ablative edge is an outer edge.

8. The process of claim 1 , wherein the ablative edge is enriched with lithium relative to a bulk of the membrane.

9. The process of claim 1 , wherein the ablative edge comprises a depth of less than about 5 μm.

10. The process of claim 1 , wherein the lithium metal phosphate is LATP.