Thin film battery substrate cutting and fabrication process
A method of fabricating a battery comprises selecting a battery substrate having cleavage planes, and cutting the battery substrate with pulsed laser bursts from a pulsed laser beam to control or limit fracture along the cleavage planes. The pulsed laser beam was also found to work well on thin substrates which are sized less than 100 microns. Before or after the cutting step, a plurality of battery component films can be deposited on the battery substrate. The battery component films include at least a pair of electrodes about an electrolyte which cooperate to form a battery.
1. A method of fabricating a battery on a battery substrate, the method comprising:
(a) selecting a battery substrate having cleavage planes;
(b) applying a plurality of pulsed laser bursts of a pulsed laser beam to the battery substrate, the pulsed laser bursts having sufficient power and duration to cut through the battery substrate substantially without causing fractures along the cleavage planes of the battery substrate; and
(c) before or after (b), depositing a plurality of battery component films on the battery substrate, the battery component films comprising at least a pair of electrodes about an electrolyte that cooperate to form a battery cell.
2. A method according to claim 1 wherein the battery substrate comprises a thickness of less than about 100 microns.
3. A method according to claim 2 comprising applying a pulsed laser beam comprising an ultraviolet laser beam having a power level of from about 5 to about 80 microjoules.
4. A method according to claim 3 comprising applying pulsed laser bursts having a duration of from about 1 to about 50 nanoseconds.
5. A method according to claim 3 comprising applying pulsed laser bursts having a pulse rate of from about 5 to about 200 Hz.
6. A method according to claim 1 comprising applying a pulsed laser beam generated by a lasing medium comprising titanium doped sapphire, and wherein the pulsed laser beam provides pulsed laser bursts having a duration of from about 50 to about 600 femtoseconds.
7. A method according to claim 6 comprising providing pulsed laser bursts having a fluence of from about 10 to about 800 J/cm 2 .
8. A method according to claim 6 wherein the pulsed laser bursts are moved across the battery substrate with a vectorial velocity of from about 0.1 to about 40 mm/s.
9. A method according to claim 1 wherein (c) is performed before (b), and to deposit on the substrate in the order of deposition, battery component films comprising a cathode current collector film, a cathode film, an electrolyte, an anode, an anode current collector film, and a protective multilayer coating.
10. A method according to claim 1 further comprising applying an edge sealant to seal a laser cut edge formed by the pulsed laser beam.
11. A method according to claim 10 comprising applying an edge sealant comprising epoxy, ceramic particle filled epoxy, metal particle filled epoxy, or any thermoset UV cured polymer.
12. A method of fabricating a battery on a battery substrate, the method comprising:
(a) selecting a battery substrate having cleavage planes;
(b) applying to the battery substrate, a plurality of pulsed laser bursts of a pulsed laser beam comprising an ultraviolet laser beam having a power level of from about 5 to about 80 microjoules, the pulsed laser bursts having sufficient power and duration to cut through the battery substrate substantially without causing fractures along the cleavage planes of the battery substrate; and
(c) before or after (b), depositing a plurality of battery component films on the battery substrate, the battery component films comprising at least a pair of electrodes about an electrolyte that cooperate to form a battery cell.
13. A method according to claim 12 wherein the battery substrate comprises a thickness of less than about 100 microns.
14. A method according to claim 12 comprising applying pulsed laser bursts having a duration of from about 1 to about 50 nanoseconds.
15. A method according to claim 12 comprising applying pulsed laser bursts having a pulse rate of from about 5 to about 200 Hz.
16. A method of fabricating a battery on a battery substrate, the method comprising:
(a) selecting a battery substrate having cleavage planes;
(b) cutting the battery substrate by applying a plurality of pulsed laser bursts having a fluence of from about 10 to about 800 J/cm 2 ; and
(c) before or after (b), depositing a plurality of battery component films on the battery substrate, the battery component films comprising at least a pair of electrodes about an electrolyte that cooperate to form a battery cell.
17. A method according to claim 16 wherein the battery substrate comprises a thickness of less than about 100 microns.
18. A method according to claim 16 comprising applying pulsed laser bursts having a pulse duration of from about 50 to about 600 femtoseconds.
19. A method according to claim 16 comprising applying pulsed laser bursts having a pulse repetition rate of from about 50 to about 1000 Hz.
20. A method according to claim 16 wherein the pulsed laser bursts are generated from a laser beam having a power density of from about 1 to about 440 J/cm 2 , and wherein (b) comprises moving the pulsed laser bursts across the battery substrate with a vectorial velocity of from about 0.1 to about 40 mm/s.