Techniques for charging and/or discharging a battery using frequency modulation
Described herein are techniques that increase the charging and/or discharging rate of a rechargeable battery, at least in part, by using frequency modulated (FM) signals having a frequency in the megahertz (MHz) frequency range. In some embodiments, the MHz frequency range may include any frequency between 0.1 MHz and 1 gigahertz (GHz). In some embodiments, a battery charger described herein may be configured to generate and transmit, to a battery, an FM signal modulated over a frequency range during a period of time, the FM signal having a frequency of at least 0.5 MHz during at least a first portion of the period of time. In some embodiments, a method described herein includes transmitting an FM signal modulated over a frequency range during a period of time and having a frequency of at least 0.5 MHz during at least a first portion of the period of time to a battery.
1. A battery charging system, comprising:
a battery; and
a battery charger, configured to:
generate a frequency modulated (FM) signal that, during a period of time:
oscillates between a first current and/or voltage level and a second current and/or voltage level; and
has a frequency of at least 0.5 megahertz (MHz) during at least a first portion of the period of time; and
apply the FM signal to at least one terminal of the battery during the period of time such that, when the FM signal has the second current and/or voltage level, a current and/or voltage at the at least one terminal of the battery is substantially zero.
2. The system of claim 1 , wherein the battery charger comprises signal generation circuitry configured to generate the FM signal having the frequency of at least 0.5 MHz during at least the first portion of the period of time.
3. The system of claim 2 , wherein the signal generation circuitry is configured to generate the FM signal having a frequency of at least 1 MHz during at least the first portion of the period of time.
4. The system of claim 2 , wherein the signal generation circuitry is configured to sweep the FM signal from a first frequency to a second frequency repeatedly during the period of time, the first frequency being at least 0.1 MHz.
5. The system of claim 2 , wherein the signal generation circuitry is configured to sweep the FM signal from a first frequency to a second frequency repeatedly during the period of time, wherein the first frequency is at least 0.5 MHz.
6. The system of claim 2 , wherein:
the signal generation circuitry is configured to generate a modulation signal having the frequency of at least 0.5 MHz during at least the first portion of the period of time; and
the battery charger further comprises modulation circuitry configured to modulate a direct-current (DC) current signal with the modulation signal to generate the FM signal at least in part by oscillating the modulation signal between open circuit current and a charging current during the period of time.
7. The system of claim 6 , wherein the battery comprises a lithium-hexafluorophosphate (LiPF6) salt.
8. The system of claim 7 , wherein the battery further comprises a lithium-bistrifluoromethanesulfonylimide (LiTFSI) salt.
9. The system of claim 1 , wherein the battery comprises an electrolyte selected from a group consisting of:
lithium-hexafluorophosphate (LiPF 6 ) in dimethyl carbonate (DMC);
lithium-bistrifluoromethanesulfonylimide (LiTFSI) in DMC;
LiPF 6 solution and LiTFSI in DMC; and
LiPF 6 in DMC and ethyl carbonate (EC).
10. A battery charger configured to:
generate a frequency modulated (FM) signal that, during a period of time:
oscillates between a first current and/or voltage level and a second current and/or voltage level; and
has a frequency of at least 0.5 megahertz (MHz) during at least a first portion of the period of time; and
apply the FM signal to at least one terminal of a battery during the period of time such that, when the FM signal has the second current and/or voltage level, a current and/or voltage at the at least one terminal of the battery is substantially zero.
11. The battery charger of claim 10 , further comprising signal generation circuitry configured to generate the FM signal having a frequency of at least 1 MHz during at least the first portion of the period of time.
12. The battery charger of claim 11 , wherein the signal generation circuitry is configured to generate the FM signal having a frequency of at least 3 MHz during at least the first portion of the period of time.
13. The battery charger of claim 11 , wherein the signal generation circuitry is configured to sweep the FM signal from a first frequency to a second frequency repeatedly during the period of time, the first frequency being at least 0.1 MHz.
14. The battery charger of claim 11 , wherein the signal generation circuitry is configured to sweep the FM signal from a first frequency to a second frequency repeatedly during the period of time, wherein the first frequency is at least 0.5 MHz.
15. The battery charger of claim 11 , wherein:
the signal generation circuitry is configured to generate a modulation signal having the frequency of at least 0.5 MHz during at least the first portion of the period of time; and
the battery charger further comprises modulation circuitry configured to modulate a direct-current (DC) current signal with the modulation signal to generate the FM signal at least in part by oscillating the modulation signal between open circuit current and a charging current during the period of time.
16. A method comprising:
applying, to at least one terminal of a battery, a frequency modulated (FM) signal modulated over a frequency range during a period of time and oscillating between a first current and/or voltage level and a second current and/or voltage level such that, when the FM signal has the second current and/or voltage level, a current and/or voltage at the at least one terminal of the battery is substantially zero,
wherein the FM signal has a frequency of at least 0.5 megahertz (MHz) during at least a first portion of the period of time.
17. The method of claim 16 , wherein the FM signal has a frequency of at least 1 MHz during at least the first portion of the period of time.
18. The method of claim 16 , wherein the FM signal has a frequency of at least 3 MHz during at least the first portion of the period of time.
19. The method of claim 16 , wherein the FM signal is swept from a first frequency to a second frequency repeatedly during the period of time, and the first frequency is at least 0.1 MHz.
20. The method of claim 16 , further comprising modulating a direct-current (DC) current signal with a modulation signal to generate the FM signal at least in part by oscillating a current of the modulation signal between an open circuit current and a charging current, wherein the modulation signal has the frequency of at least 0.5 MHz during at least the first portion of the period of time.