Pulsed laser cutting of thin film battery
A battery fabrication method comprises forming at least one battery cell on a battery substrate by 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. An overlying protective multilayer coating is formed over the battery cell. A plurality of pulsed laser bursts of a pulsed laser beam is applied to the battery substrate, the pulsed laser bursts having sufficient power and duration to cut through the battery substrate and the overlying protective multilayer coating.
1. A battery fabrication method comprising:
(a) forming at least one battery cell on a battery substrate by 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;
(b) forming an overlying protective multilayer coating over the at least one battery cell; and
(c) 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 and the overlying protective multilayer coating.
2. A method according to claim 1 wherein (b) comprises forming a protective multilayer coating conforming to the external shape of the battery cell.
3. A method according to claim 1 wherein (b) comprises forming a protective multilayer coating comprising at least one of:
(i) a polymer layer;
(ii) a ceramic layer; and
(iii) a packaging layer.
4. A method according to claim 1 wherein (b) comprises forming a protective multilayer coating comprising a polymer layer superimposed on a packaging layer.
5. A method according to claim 1 wherein the pulsed laser beam forms a laser cut edge, and comprising applying an edge sealant to seal the laser cut edge.
6. A method according to claim 1 wherein (c) comprises applying a pulsed laser beam comprising an ultraviolet laser beam.
7. A method according to claim 1 wherein (c) comprises applying a pulsed laser beam comprising at least one of the following:
(i) a power level of from about 5 to about 80 microJoules;
(ii) a duration of from about 1 to about 50 nanoseconds;
(iii) a pulse rate of from about 5 to about 200 Hz; and
(iv) a fluence of from about 10 to about 800 J/cm 2 .
8. A method according to claim 1 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 comprising selecting a battery substrate comprising a thickness of less than about 100 microns.
10. A method according to claim 1 comprising selecting a battery substrate comprising cleavage planes, and wherein (c) comprises applying the pulsed laser bursts with a sufficient power and duration to cut through the battery substrate and the overlying protective multilayer coating substantially without causing fractures along the cleavage planes of the battery substrate.
11. A battery fabrication method comprising:
(a) forming at least one battery cell on a battery substrate by 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;
(b) forming an overlying protective multilayer coating over the at least one battery cell;
(c) generating a pulsed laser beam from a lasing medium comprising a solid-state rod material; and
(d) applying a plurality of pulsed laser bursts of the pulsed laser beam to the battery substrate, the pulsed laser bursts having sufficient power and duration to cut through the battery substrate and the overlying protective multilayer coating.
12. A method according to claim 11 wherein the lasing medium is within a light resonator comprising an elliptical cavity having reflective surfaces which reflect photons emitted from a light source toward the lasing medium.
13. A method according to claim 11 wherein the lasing medium comprises titanium doped sapphire, Nd:YAG, or chromium ion doped ruby.
14. A method according to claim 11 wherein the pulsed laser beam comprises pulse durations in the nanoseconds or femtoseconds.
15. A battery fabrication method comprising:
(a) forming at least one battery cell on a battery substrate by 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;
(b) forming an overlying protective multilayer coating over the battery cell; and
(c) cutting the battery substrate and the overlying protective multilayer coating by applying a plurality of pulsed laser bursts having a fluence of from about 10 to about 800 J/cm 2 .
16. A method according to claim 15 wherein (b) comprises forming a protective multilayer coating conforming to the external shape of the at least one battery cell.
17. A method according to claim 15 wherein (b) comprises forming a protective multilayer coating comprising at least one of:
(i) a polymer layer;
(ii) a ceramic layer; and
(iii) a packaging layer.
18. A method according to claim 15 wherein (b) comprises forming a protective multilayer coating comprising the polymer layer superimposed on a packaging layer.
19. A method according to claim 15 wherein (c) comprises applying pulsed laser bursts from a pulsed laser beam comprising an ultraviolet laser beam.
20. A method according to claim 15 wherein (c) comprises applying pulsed laser bursts comprising at least one of the following:
(i) a pulse duration of from about 50 to about 600 femtoseconds; and
(ii) a pulse repetition rate of from about 50 to about 1000 Hz.