EP-4738643-A1 - CHARGE AND DISCHARGE CONTROL SYSTEM FOR A ZINC-AIR BATTERY

Abstract

A system including a plurality of electrochemical cells, charge switching circuitry, and discharge switching circuitry. The charge switching circuitry and the discharge switching circuitry may be controlled to substantially isolate charging and discharging of the plurality of cells.

Inventors

• ALEXANDER, Ryan Warren
• LUU, Devin K.
• DE KONING, PETRUS THEODORUS
• NADEN, MARK
• ZHANG, XIAOGE GREGORY

Assignees

• E-Zinc Inc.

Dates

Publication Date

20260506

Application Date

20251030

Claims (15)

1. An electrochemical cell system, said system comprising: first and second cells, the first and second cells each including a negative charge terminal and a positive charge terminal and a1 negative discharge terminal and a positive discharge terminal, the electrochemical cell system adapted to discharge power to a current sink and to charge based on power from a current source; first discharge switching circuitry operably coupled to the positive discharge terminal of the first cell, the first discharge switching circuitry operable to selectively provide current to the current sink from the first cell; second discharge switching circuitry operably coupled to the positive discharge terminal of the second cell and the negative discharge terminal of the first cell, the second discharge switching circuitry operable to selectively provide current to the current sink from the second cell; and a controller configured to direct operation of the first and second discharge switching circuitry to substantially isolate charging and discharging of the first and second cells.
2. The electrochemical cell system of claim 1, comprising: first charge switching circuitry operably coupled to the positive charge terminal of the first cell, the first charge switching circuitry operable to selectively provide current output from the current source to the positive charge terminal of the first cell; and second charge switching circuitry operably coupled to the positive charge terminal of the second cell, the second charge switching circuitry operable to selectively provide the current output from the current source to the positive charge terminal of the second cell, wherein the second charge switching circuitry receives the current output from the current source via at least one of the first cell and the first charge switching circuitry.
3. The electrochemical cell system of claim 2, wherein receipt of current output from the first cell in the second charge switching circuitry includes receiving the current output from the current source via the negative charge terminal of the first cell, and wherein receipt of current output from the first charge switching circuitry includes receiving the current output from the current source via at least one of a direct connection to the first charge switching circuitry and an indirect connection to the first charge switching circuitry at the positive charge terminal of the first cell.
4. The electrochemical cell system of claim 2, wherein at least one of the first charge switching circuitry and the second charge switching circuitry is operable to selectively bypass current flow into the positive charge terminal of the first cell to provide current from the current source to the second charge switching circuitry.
5. The electrochemical cell system of claim 4, wherein: first charge switching circuitry selectively bypasses current flow into the positive charge terminal of the first cell by directing current to a node of the first cell that is connected to the negative charge terminal of the first cell and the second charge switching circuitry; or, second charge switching circuitry selectively bypasses current flow into the positive charge terminal of the first cell by disconnecting from the negative charge terminal of the first cell and connecting to the positive charge terminal of the first cell.
6. The electrochemical cell system of claim 2, wherein the controller is operable to selectively discharge power from one or both of the first and second cells, and wherein the controller is operable to selectively charge one or both of the first and second cells.
7. The electrochemical cell system of claim 6, wherein the controller is operable to control whether one or both of the first and second cells is being: discharged by selectively bypassing the first and second cells via operation of the first and second discharge switching circuitry; or, charged by selectively bypassing the first and second cells via operation of the first and second charge switching circuitry.
8. The electrochemical cell system of any one of claims 1 to 7, wherein the first discharge switching circuitry is operable to selectively provide current to the current sink from the first cell via the positive discharge terminal of the first cell, and wherein the second discharge switching circuitry operable to selectively provide current to the current sink from the second cell via the positive discharge terminal of the second cell.
9. The electrochemical cell system of any one of claims 1 to 8, wherein: (a) the current sink is a boost converter operable to convert power from the electrochemical cell system to power an external load; (b) the current source is a buck converter operable to convert external power for charging the electrochemical system; or, (c) both (a) and (b).
10. The electrochemical cell system of claim 1, wherein: (a) the first discharge switching circuitry is operable to selectively bypass current flow from the positive discharge terminal of the first cell by coupling the negative discharge terminal of the first cell to the current sink instead of the positive discharge terminal of the first cell; or, (b) the second discharge switching circuitry is operable to selectively bypass current flow from the positive discharge terminal of the first cell by disconnecting the negative discharge terminal of the first cell.
11. The electrochemical cell system of claim 2, wherein the first charge switching circuitry includes a first single-sided MOSFET with a first body diode configured to substantially block current flow from the positive charge terminal of the second cell to the negative charge terminal of the first cell.
12. The electrochemical cell system of claim 11, wherein a sensor is coupled to the first single sided MOSFET to provide an output that confirms the first single sided MOSFET is operational to avoid conduction through the first body diode while charging the first cell.
13. The electrochemical cell system of claim 11 or claim 12, wherein: (a) a construction of the first and second cells substantially limits current flow through the first body diode from the negative charge terminal of the first cell to the positive charge terminal of the second cell; (b) the first charge switching circuitry includes a second single sided MOSFET configured to selectively bypass the charging of the first cell; (c) in the first charge switching circuitry includes a first double sided MOSFET operable to selectively control charging of the first cell; or, (d) any combination of (a), (b) and (c).
14. Switching circuitry for an electrochemical cell system including first and second cells, the first and second cells each including a negative charge terminal and a positive charge terminal and a negative discharge terminal and a positive discharge terminal, the electrochemical cell system adapted to discharge power to a current sink and to charge based on power from a current source, the switching circuitry comprising: a first MOSFET including a first body diode, the first MOSFET connected between the negative charge terminal of the first cell and the positive charge terminal of the second cell, the first MOSFET being operable to selectively control charging of the first cell based on power from the current source, the first body diode of the first MOSFET is configured to substantially block current flow from the positive charge terminal of the second cell to the negative charge terminal of the first cell; and a second MOSFET connected between the positive charge terminal of the first cell and the positive charge terminal of the second cell, the second MOSFET being operable to selectively bypass charging of the first cell.
15. The switching circuitry of claim 14, wherein: (a) a sensor is coupled to the first MOSFET to provide an output that confirms the first MOSFET is operational to avoid conduction through the first body diode while charging the first cell; (b) a construction of the first and second cells substantially limits current flow through the first body diode from the negative charge terminal of the first cell to the positive charge terminal of the second cell; or, (c) both (a) and (b).

Description

FIELD OF INVENTION The present disclosure relates to the field of zinc-air batteries, and more particularly to a charge and discharge configuration for a zinc-air battery. BACKGROUND The zinc-air battery technology has been known for over 100 years but has yet to be successfully commercialized. In a conventional charge cycle, an electrolyte comprising zinc hydroxide releases zinc metal in a charge section, which precipitates as a solid and accumulates in a discharge section. During discharge, the solid zinc metal is converted back to zinc hydroxide, liberating electrons in the process. The charging and discharge modes of operation for zinc-air batteries are operable via separate terminals, which is a deterrent against use of charging and discharging platforms that are commercially available for other battery technologies. SUMMARY In general, one innovative aspect of the subject matter described herein can be embodied in an electrochemical cell system. The system may include first and second cells each with a negative charge terminal and a positive charge terminal and a negative discharge terminal and a positive discharge terminal. The electrochemical cell system may be adapted to discharge power to a current sink and to charge based on power from a current source and may include first discharge switching circuitry operably coupled to the positive discharge terminal of the first cell. The first discharge switching circuitry may be operable to selectively provide current to the current sink from the first cell. The electrochemical cell system may include second discharge switching circuitry operably coupled to the positive discharge terminal of the second cell and the negative discharge terminal of the first cell. The second discharge switching circuitry may be operable to selectively provide current to the current sink from the second cell. The electrochemical cell system may include a controller configured to direct the operation of the first and second discharge circuitry to substantially isolate charging and discharging of the first and second cells. For instance, the first and second discharge circuitry may prevent simultaneous charging and discharging of the first and second cells. The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. In particular, one embodiment includes all the following features in combination. In some embodiments, the electrochemical cell system may include first charge switching circuitry operably coupled to the positive charge terminal of the first cell. The first charge switching circuitry may be operable to selectively provide current output from the current source to the positive charge terminal of the first cell. The electrochemical cell system may include second charge switching circuitry operably coupled to the positive charge terminal of the second cell. The second charge switching circuitry may be operable to selectively provide the current output from the current source to the positive charge terminal of the second cell, where the second charge switching circuitry may receive the current output from the current source via at least one of the first cell and the first charge switching circuitry. In some embodiments, receipt of current output from the first cell in the second charge switching circuitry may include receiving the current output from the current source via the negative charge terminal of the first cell, and where receipt of current output from the first charge switching circuitry may include receiving the current output from the current source via at least one of a direct connection to the first charge switching circuitry and an indirect connection to the first charge switching circuitry at the positive charge terminal of the first cell. In some embodiments, at least one of the first charge switching circuitry and the second charge switching circuitry may be operable to selectively bypass current flow into the positive charge terminal of the first cell to provide current from the current source to the second charge switching circuitry. In some embodiments, the first charge switching circuitry may selectively bypass current flow into the positive charge terminal of the first cell by directing current to a node of the first cell that is connected to the negative charge terminal of the first cell and the second charge switching circuitry. In some embodiments, the second charge switching circuitry may selectively bypass current flow into the positive charge terminal of the first cell by disconnecting from the negative charge terminal of the first cell and connecting to the positive charge terminal of the first cell. In some embodiments, the controller may be operable to selectively discharge power from one or both of the first and second cells, and where the controller may be operable to selectively charge one or both of the first and second cells. In some embodiments, the controller may be