WO2016198868A1

WO2016198868A1 - Electrochemical cell

Info

Publication number: WO2016198868A1
Application number: PCT/GB2016/051700
Authority: WO
Inventors: John Collins
Original assignee: C Tech Innovation Ltd
Current assignee: C Tech Innovation Ltd
Priority date: 2015-06-11
Filing date: 2016-06-09
Publication date: 2016-12-15
Anticipated expiration: 2017-12-11
Also published as: GB201510142D0

Abstract

An electrochemical cell has removable electrodes. The removable electrodes are held and sealed the cell body by means of a treaded bolt engaging an internally threaded hole.. Removable electrodes of different thickness are accommodated by adjusting the position of said externally threaded shank with respect to the internally threaded tube.

Description

ELECTROCHEMICAL CELL

Technical Field

This invention relates to an electrochemical cell – a device for carrying out electrochemical reactions with products either in solution or adhering to the surfaces of electrodes.

Background

Electrochemical cells are in common use in industry for a wide range of reactions and are also used in research laboratories for developing new industrial processes and for scientific investigations.

Electrochemical cell contain, amongst other components, electrodes to make the electrical circuit, and means to introduce liquids; in some designs the cells additionally contain, among other things, gases, semipermeable membranes to separate different liquid streams but allow the transfer of ions, spacers to ensure correct spacing of membrane and electrodes. All of these components must be assembled in a device that does not leak and that requires the use of multiple gaskets, O-rings and in some cases sealing compounds. This means that electrochemical cells are, by their nature time-consuming to disassemble and reassemble and prone to leaking if incorrectly assembled. Additionally there is limited scope once an electrochemical cell is built to change the operating parameters of the design such as the thickness of the electrodes or the spacing between the electrodes and the membranes and the associated hydrodynamic flow arrangements.

Disclosure of Invention

According to the present invention an electrochemical cell has a cell body with a pair of end plates and with at least one electrolyte flow path into and out of the cell body wherein the electrodes of the cell is removable, said removable electrodes being urged and sealed against the cell body by back plates urged by engaging first bolts in internally threaded holes in the pair of end plates, accommodation of electrodes of different thicknesses being by adjusting the position of said bolt with respect to the internally threaded hole.

In this way and in that electrodes of different thicknesses may be used by adjusting the position of first bolt with respect to the internally threaded hole.

In one embodiment one or more removable manifold inserts are provided in the electrolyte flow paths into the cell body this permitting modification of electrolyte flows within the cell body without the need to modify the cell body or other components of the cell.

Other optional features of the invention are set out in the claims.

The invention allows for the use of electrodes of variable thickness and the use of different liquid manifolds suitable for different liquids or spacing of components, without the need for additional components and in such a way that the device can be quickly and easily disassembled and assembled, as will routinely be the case when carrying out laboratory work for example.

The facility to use electrodes of variable thickness is important when carrying out research and development into electrode materials and compatibilities. The invention provides this facility by the use of an electrode support assembly which operates independently of the clamping of the cell components between the end-plates and at the same time provides an electrochemical cell that overcomes the shortcomings of known electrochemical cells.

In one embodiment of the invention the cell comprises removable manifold inserts. This provides the ability to modify the hydrodynamic flow. The removable inserts distribute the liquid electrolyte flow in three dimensions as the liquid enters the cell.

Brief Description of Drawings

An example of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is an external view of an assembled cell according to the invention;

Figure 2 is an exploded drawing of the cell of figure 1, and

Figure 3 is a vertical section of the cell of figure 1 on the line X-X.

Description of example

In the figures an electrochemical cell 1 has a cell body 3, which is in two

cell body halves

3A and 3B, with a pair of gaskets 4 sealing between the two

halves

3A and 3B. The gaskets 4 have central apertures, in which a cell membrane 5 is mounted. The cell body has a central aperture 6. The cell body halves have seats 7 within their central apertures, aperture 6 of the cell body 4 are closed by

electrodes

8A and 8B sealed against seats 7 gaskets 9.

The

cell body halves

3A and 3B and gaskets 4 are penetrated by holes 10, through which pass bolts 11 attached rigidly one end plate 12A of a pair of end plates 12 and through the other end plate 12B of the pair, hand nuts 13 are screwed onto each of the bolts 11. Tightening the hand screws 13 clamps the pair of endplates 12 to the outside faces 10 of the

cell halves

3A and 3B.

Conductors 15 pass perpendicularly through (but without contacting threaded holes 30 in each of the

end plates

12A and 12B and also through holes in electrode thrust plate 16 and engaging in threaded holes in electrode back plates 14 to make electrical contact with the

electrodes

8A and 8B. The outer ends of the conductors 15 have external treads 20 onto which electrical contacts 21 are made, and the contacts are held in place with nuts 22 engaging the treads 20.The conductors 15 pass axially through hollow bots 18, the bolts 18 engage in the threaded holes 30. The bolts 18 have knurled knobs 19 to enable the bolts 18 to be turned in the treaded holes 30, the ends of the bolts engage the electrode thrust plates 16 bearing against the electrode back plates 14 which in turn bear on the

electrodes

8A and 8B pushing them against gaskets 9 in seats 7, so sealing the cell body. The material of the

back plates

12A and 12B, bolts 18 and knurled knob 19 are chosen to insulate the conductors 15. By turning the bolts 18 inwards or outwards in treaded holes 30, the ends 31 of the bolts move inwards or outwards, allowing

electrodes

8A and 8B of different sizes to be accommodated.

The inner faces 23 of each

cell body half

3A and 3B have recesses 24 into which are fitted removable manifold inserts 25. The electrolyte flows into the cell 3 through ducts 26 from which lateral ducts 27 then though the manifold inserts 25. The manifold inserts 25 can have different patterns of manifold design as required. They are easily removable. As well as distributing the liquid flow they support the cell membrane 5, preventing it from intruding into the electrolyte flow path.

The side of the cell 3 is penetrated by small sealable tubes 28 to enable samples of the electrolyte in the cell when in use to be taken for analysis purposes.

To enable assembly and disassembly to be carried out easily, a stand 2 is provided to hold the cell top and bottom. In use, with the cell demounted from stand 2, legs 29 are provided at the bottom of each end plate 12 on which the cell stands.

Assembly and disassembly of the cell of this invention can be carried out without the use of tools. The electrodes 8 are compressed against their gaskets 9 against seats 7 by the treaded shank 18 and the whole cell body is tightened of hand operated nuts 13 being tightened on bolts 11. The shank 18 coupled to electrical connector 22 so serve as the means of current transfer into and out of the cell.

The electrodes are simple rectangular pieces of material and removable. The thickness of the electrodes can be varied easily by screw in or out the shank 18 to compensate for any changes in thickness.

The gaskets 9, shown in figure 3 compressed between seats 7 and the electrodes 8 by the shank 18, can be replaced by alternatives such a sealant or O-rings.

The cell shown in figures 1 to 3 is an example of the invention and is not in any way limiting the invention to that specific embodiment.

Claims

An electrochemical cell having a cell body with a pair of end plates and at least one electrolyte flow path into and out of the cell body wherein the electrodes of the cell is removable, said removable electrodes being urged and sealed against the cell body by a back plates urged by engaging first bolts in an internally threaded holes in the pair of end plates , accommodation of electrodes of different thicknesses being by adjusting the position of said bolt with respect to the internally threaded hole.
An electrochemical cell according to claim 1having a pair of endplates, said end plates being bolted together around the cell body and each end plate having the treaded shank passing through.
An electrochemical cell according to claim 2 held together by nut and bolt assemblies holding the end plates together, the nuts being hand-nuts to allow assembly or disassembly of the electrochemical cell.
An electrochemical cell according to claim 1, 2 or 3 in which electrical conductors engaging with the electrodes pass through the first bolts pass through the first bolts.
An electrochemical cell according to any preceding claim in which one or more removable manifold inserts are provided in the electrolyte flow paths into the cell body permitting modification of electrolyte flows within the cell body without the need to modify the cell body or other components of the cell.
An electrochemical cell according to claim 5 having a cell membrane in which the one or more removable inserts aid maintenance of the position of the cell membrane.
An electrochemical cell according to any pre ceding claim in the cell body is fluid tight by virtue of the removable electrodes being sealed against seats in the cell body under pressure of the threaded shank.