Standby electrical energy storage devices

1. A standby structural composite electrical energy storage device which can be used in place of an existing panel or element that forms part of a structural body, the energy storage device comprising:

a first electrode structure and a second electrode structure each of said first and second electrode structures being formed as a composite material comprising electrically conductive fibres in a respective electrode binder matrix;

a separator structure, said separator structure being formed as a composite material comprising electrically insulating fibres in a separator binder matrix ;

a reservoir structure, said reservoir structure being formed as a composite material comprising electrically insulating fibres in a reservoir binder matrix;

said electrode, separator, and reservoir structures being encapsulated in a composite binder matrix to form an integral, cured fibre polymer composite wherein the separator structure separates the first and second electrode structures respectively;

at least one electrolyte void between said first and second electrode structures, said electrolyte void being capable of being filled with an electrolyte; and

at least one reservoir comprising an electrolyte, said reservoir being at least one reservoir void in the reservoir structure, wherein said reservoir is operably linked by a valve to said at least one electrolyte void, such that operation of said valve allows the electrolyte void to be charged with the electrolyte.

2. The device according to claim 1 , wherein the device comprises a vent system.

3. The device according to claim 1 wherein the valve is mechanical, chemical, electromechanical or thermal.

4. The device according to claim 1 wherein the valve is a mechanical valve that comprises a Micro Electro-Mechanical Systems (“MEMS”) actuator.

5. The device according to claim 1 comprising a liquid or gel electrolyte.

6. The device according to claim 1 , wherein the energy storage device is a composite battery or a composite supercapacitor.

7. The device according to claim 1 wherein the first and second electrodes form anode and cathode structures to form a composite battery, and said device further comprises nickel-zinc, nickel-iron, nickel-cadmium, nickel metal hydride, lead acid or silver-zinc, or Li-ion electrochemically active materials.

8. The device according to claim 1 , wherein at least one of the first and second electrode and the separator structure contains a porous additive which increases access of the electrolyte when present in said structure.

9. The device according to claim 1 , wherein the electrolyte void is a porous material, structural lattice, or a partially bonded separator structure.

10. A method of activating a standby structural composite electrical energy storage device which can be used in place of an existing panel or element that forms part of a structural body, the method comprising:

providing a device having a first electrode structure and a second electrode structure, each of said first and second electrode structures being formed as a composite material comprising electrically conductive fibres in a respective electrode binder matrix;

a separator structure, said separator structure being formed as a composite material comprising electrically insulating fibres in a separator binder matrix;

a reservoir structure, said reservoir structure being formed as a composite material comprising electrically insulating fibres in a reservoir binder matrix;

said electrode, separator, and reservoir structures being encapsulated in a composite binder matrix to form an integral, cured fibre polymer composite, wherein the separator structure separates the first and second electrode structures respectively;

at least one electrolyte void between said first and second electrode structures, said electrolyte void being capable of being filled with an electrolyte; and

at least one reservoir comprising an electrolyte, said reservoir being at least one reservoir void in the reservoir structure, wherein said reservoir is operably linked by a valve to said at least one electrolyte void, such that operation of said valve allows the electrolyte void to be charged with the electrolyte; and

causing the valve to open, causing the electrolyte to be transferred from the reservoir to the at least one electrolyte void.

11. A panel on a vehicle, vessel, or craft, comprising at least one standby structural composite energy storage device used in place of a panel or element that would otherwise serve as a structural component of the vehicle, vessel, or craft, wherein the composite energy storage device includes:

a first electrode structure and a second electrode structure, each of said first and second electrode structures being formed as a composite material comprising electrically conductive fibres in a respective electrode binder matrix;

a separator structure, said separator structure being formed as a composite material comprising electrically insulating fibres in a separator binder matrix;

a reservoir structure, said reservoir structure being formed as a composite material comprising electrically insulating fibres in a reservoir binder matrix;

said electrode, separator, and reservoir structures being encapsulated in a composite binder matrix to form an integral, cured fibre polymer composite wherein the separator structure separates the first and second electrode structures respectively;

at least one electrolyte void between said first and second electrode structures, said electrolyte void being capable of being filled with an electrolyte; and

at least one reservoir comprising an electrolyte, said reservoir being at least one reservoir void in the reservoir structure, wherein said reservoir is operably linked by a valve to said at least one electrolyte void, such that operation of said valve allows the electrolyte void to be charged with the electrolyte.