GB1574071A - Lithium halide cells and batteries - Google Patents

Description

(54) LITHIUM HALIDE CELLS AND BATTERIES (71) We, CATALYST RESEARCH CORPOR ATION, a Corporation organised under the laws of the State of Maryland, United States of America, of 1421 Clarkview Road, Baltimore, Maryland 21209, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be described in and by the following statement: - The present invention relates to lithium halide cells and batteries and to improved methods for the manufacture of them. In particular the present invention is concerned with the manufacture of cells or batteries of this kind which form the subject of our Application No. 13489/76 (Serial No. 1,542,325) with a view to providing useful improvements therein.

Primary cells having charge transfer complexes, such as iodine-containing materials are generally well known. High energy density batteries utilizing lithium anodes and cathodes made of organic materials, such as polycyclic aromatic compounds, organic polymers, heterocyclic nitrogencontaining compounds and the like and a halide such as iodine have been proposed; while cathode compositions comprising a mixture of iodine and poly-2-vinylpyridine.

n12 or poly-2-vinylquinoline. nI2, wherein n = 2-15 are described in United States Patent Specification No. 3,674,562, which is incorporated herein by reference. Cathode materials of this latter type are typically pliable, plastic-like solids having a flowable viscosity.

Lithium halide batteries produced according to the present invention are typically used with implantable prosthetics, such as cardiac pacemakers. For such application, it is necessary that the battery be physically small and highly reliable. In attaining high reliability, both the design of and the methods for manufacturing the battery are of great importance.

Of the many problems that can arise from poor design or manufacturing processes of lithium halide cells, obtaining satisfactory sealing of the depolarizer within the container is one of the most critical. In many processes, it is difficult, if not impossible, to determine whether a battery will leak until it has been completely assembIed with its hermetic seal and tested. Failure to achieve a leak-proof seal requires discarding of the battery with little or no saIvage. Moreover, it is often difficult to determine whether a lead-proof seal has been achieved until the battery has been placed in service.

Our copending Application No. 13489/76 (Serial No. 1,542,325) describes and claims a lithium-iodine primary cell or battery and a method for making them which go well towards overcoming these and other problems, but the present invention provides further improvements or modifications, which are also applicable to other lithiumhalide batteries.

According to the present invention a method is provided for making a lithium halide battery which comprises the steps of: (A) forming a lithium anode receiving vessel having a cathode lead em bedded within the vessel by: - (i) folding a lithium sheet into the form of a vessel having an open ing; (ii) positioning a cathode lead hav ing insulation thereon within said vessel such that one end of the lead is within the vessel to serve as a cathode current col lector and the other extends be tween at least two folds of the lithium to the outside of the vessel; (iii) pressing the folds together to embed the cathode lead there between and to form a vessel in which the cathode lead is ex posed within the vessel and at the opening;.

(iv) mounting an anode lead so that it extends to the exterior of the vessel; (B) heating a cathode material to a flow able consistency; (C) filling said vessel less than full with said cathode material and chilling said vessel and material to solidify the material; and (D) while the material is in the solidified state, positioning within said opening a lithium lid member having a shape substantially the same as said open ing and crimping the lithium of the vessel extending beyond the unfilled portion over the lid member and applying pressure so as to cold bond the crimped portion to the lid to seal the cathode material within the ves sel.

As will appear from the following description, this invention can provide a lithium anode cell having one defined end and a flat lithium seal on the other to permit the fabrication of cells of varying lengths from one set of vessel forming moulds. The cathode lead is largely embedded within the lithium encasing vessel to maximize any possible path for depolarizer leakage, while a cathode current collector assembly is provided which is positioned within the lithium receiving vessel so as to be electrically isolated from the lithium encasement vessel.

By using the present invention, lithiumhalide primary cells can be made having a variety of lengths utilizing a single mould.

In a preferred method, the cathode and anode leads, respectively, are embedded within the side walls of a lithium anode receiving vessel to minimize any possibility of depolarizer leakage. Generally, the method of the present invention comprises utilizing a mould in which only one end of the battery configuration is defined. Preferably, the defined end includes rounded corners, as well as a rounded end portion.

Actual assembly of the battery must be carried out in a dry room having a relative humidity of preferably less than 2%.

According to one method a substantially rectangular sheet of lithium material is positioned over a half-mould so as to extend beyond the edges of the mould cavity, preferably with a parting sheet interposed therebetween. A cavity conforming halfmember having a configuration substantially identical to the half-mould cavity is positioned over the lithium sheet and pressed into the mould cavity to conform the lithium sheet thereto. While in the cavity, a cathode assembly having a portion which conforms to the end of the halfmould is positioned on the conforming halfmember is positioned over the first halfmember and the cathode assembly. One side of the lithium blank is then folded over the second half-member and the lead from the cathode assembly is bent over this folded side so as to surround the lithium fold. The other side of the lithium blank is then folded to lie over both the cathode lead and the first folded side. The halfmembers together with the folded lithium are removed from the half-mould cavity, and the defined bottom edge of the lithium is trimmed and bent to conform to the rounded corners of the half-members, so as to form the rough lithium anode receiving vessel. Thereafter, the half-members together with the formed lithium anode receiving vessel positioned thereon are repositioned within the half-mould cavity so that an anode current collector can be bonded to the exterior. The second half of the mould is attached to the half-mould and the half-members are compressed to bond all lithium folds together. The formed lithium receiving vessel is thereafter removed from the mould and X-rayed.

The formed lithium receiving vessel is filled with cathode material which had been heated to a flowable consistency and is solidified, after filling, by cooling the filled vessel. A lithium cap is positioned on top of and in contact with the solidified cathode material. The sides and edges of the lithium receiving vessel are thereafter folded over the cap member, but not over the cathode and anode leads. The folded lithium material is pressed to cold bond the folded material to the lid. The projecting anode and cathode leads are connected to extension leads positioned substantially parallel to and spaced away from the folded lithium top member A metal cover having a pair of terminal pins extending therethrough and hermetically sealed therein by means of glass-tometal seals is positioned substantially parallel to the lithium lid and electrically connected to an associated lead extension.

A pair of ceramic spacer members are positioned about each of the terminal extenders to maintain the cover in spaced apart relationship from the top of the lithium receiving member.

The primary battery is completed by positioning the cell thus formed within a stainless steel envelope and hermetically sealing the cover to said envelope, preferably by welding. Preferably, the receiving vessel is provided with a fluoro-plastic coating or sheathing.

The method generally described permits the fabrication of cells and batteries in which the cathode lead is positioned within the lithium receiving vessel wall. Additionally, the method of the present invention permits the manufacture of a primary cells of differing lengths using the same moulds.

Other features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, taken in conjunction with the accompanying drawings.

In the drawings: - Figures 1 to 7 are illustrative representations of preferred methods steps for fabricating a lithium anode receiving vessel; Figures 8 is an elevation of the completed lithium anode receiving vessel; Figures 9 and 10 are sections taken along the lines IX-IX and X-X of Figure 8, showing the anode and cathode leads, respectively, embedded within the lithium anode receiving vessel; Figures 11 to 13 are illustrative of a method for sealing the cathode-depolarizer material within the receiving vessel; Figure 14 is an elevation of part of the receiving vessel with lead extensions connected to the cathode and anode leads; Figure 15 is a plan view of the receiving vessel shown in Figure 14 with the lead members turned through 90 ; Figure 16 is a sectional elevation of a cover member showing the terminal pins hermetically sealed therein; Figure 17 is an enlarged elevation of the receiving vessel and cover plate with the terminals and anode and cathode leads electrically connected thereto; Figures 18 and 19 are elevations showing respectively the positioning of a spacer member between the cover and receiving vessel and the diagrammatic insertion of the receiving vessel into an outer stainless steel case.

The following description sets forth preferred methods of fabricating the lithiumhalogen primary cells of the present invention.

Referring to Figure 1, a half-mould 9 with cavity 10 is shown, which defines the preferred outer contour of the cells. Cavity 10 includes an end portion 11 which defines the fixed end of a lithium anode receiving vessel. Preferably, the fixed end 11 is provided with rounded corners 11a and llb.

Also, it is preferred that the sidewall of the cavity 10 should be rounded.

The fabrication of each cell is begun by positioning over the half-mould 9 and cavity 10 a parting sheet 12, for example one of clear transparent polyethylene material, to facilitate removal of the lithium anode from the mould. Over the parting sheet 12 is positioned a thin sheet 15 of lithium, preferably one from 010 to 100 inches in thickness, used to form a lithium anode receiving vessel. This sheet 15 includes first and second side edges 16 and 17, respectively, which extend beyond the cavity 10 of mould 9. Each side extends beyond the cavity by an amount at least greather than one-half the width of the cavity. Further, the lithium sheet 15 is positioned to extend beyond end 11 of the cavity 10 and prefer- ably includes a tab extension 18. Sheet 15 may be of any desired length, in the elevation of the length of the mould, but as shown it is approximately equal to one-half the length of the mould cavity 10. While the length is not critical except as to the desired specifications of the final battery, the length is limited by the length of the half-member 22 which is described below.

With reference to Figure 2, a second mould part 19 is shown with a member 21 and a half-member 22, which substantially conforms to cavity 10. Half-member 22 is positioned over sheet 15 and pressed into cavity 10 to contour the sheet 15 to the perimeter of cavity 10. With half-member 22 positioned within the cavity over the lithium anode, the cathode assembly 25 is arranged so as to lie on half-member 22 with its lead projecting over tab 18.

Referring to Figure 3, the cathode assembly 25 comprises a cathode lead 26 encased in plastic sheathing 27. Cathode lead 26 is preferably made from a thin strip of zirconium or platinum. Preferably, sheathing 27 is a fluoroplastic such as the one which is known under the Registered Trade Mark "Halar". Cathode assembly 25 also includes a support positioning frame 28 of substantially open rectangular shape having an end configured to conform to end portion 11 of cavity 10. The perimeter of frame 18 is sized to define substantially the inner cross-sectional perimeter of the lithium vessel. Frame 28 is made from a fluoroplastic, such as "Halar", and is attached to the cathode lead by means of heat welding or cementing.

Because of the shape and size of the frame 28, the cathode assembly 25, and in particular the cathode lead 26, can be accurately and uniformly positioned during manufacture of cells. Preferably, the anode lead 30 having a fluoroplastic insulation 31, preferably on made of "Halar", is temporarily attached to the cathode lead insulation 27 by means of an attachment 32 such as tape. While not essential, the attachment of the anode lead to the cathode lead prior to positioning the cathode lead greatly facilitates fabrication of the cell. After the cathode assembly 25 has been positioned on the first half-member 22, the second halfmember 23 is aligned and positioned over cathode assembly 25 by means of pins 24.

The second half-member 23 includes a recess 23a to accommodate the cathode lead.

With reference to Figure 4, the side 16 of lithium sheet 15 is folded over second halfmember 23. Cathode lead 26 is then bent over side 16 and positioned in abutment therewith. If anode lead 30 is attached to the cathode lead it too is moved so as to be parallel to cathode lead 26, but anode lead 30 is not positioned under fold 16.

Thereafter, side 17 is folded over cathode lead 26 and side 16. However, if anode lead 30 is attached to cathode lead 26, side 17 must be positioned under anode lead 30 by lifting anode lead 30 out of the way during the folding operation.

The mould 9 is thereafter removed, as shown in Figure 5, and the top portion of the lithium sheet 15, including tab 18, is compressed about the radius of half-members 22 and 23, as is more clearly shown in Figure 5a. Excess material is preferably trimmed from corners 34 and the edges pressed to substantially conform the lithium to the contours of the half-members.

The mould 9 is then repositioned as shown in Figure 6 and a small lithium sheet 35 is cemented to the side of the lithium vessel, preferably the same side as that in which the cathode lead 26 is embedded, so as to overlie and contact anode lead 30.

The lithium sheet 35 in combination with the anode lead 30 forms the anode current collector for the battery assembly. Preferably, a reinforcing patch of lithium 36 is bonded over patch 35, as shown in Figure 7, and embeds the anode lead 30 within the lithium wall formed by patch 36. Thereafter, the second half 9a of the mould 9 having conformity cavity 10a is positioned on mould 9 by means of pins 8. Mould 9 and second part 19 are pressed together (ca. 700 psi) so as to cold bond all of the seams. The lithium anode receiving vessel with the cathode assembly is then removed and X-rayed to ensure that no unwanted openings exist. The pressure asserted by the moulds is sufficient adequately to embed both the cathode and anode leads within the lithium. Most importantly, the cathode lead is embedded along at least the length of the vessel to maximize the length of any possible leakage path.

It is important to note that while the use of mould 9 has been shown in process steps illustrated at Figures 1 to 6, it is possible to defer using the mould 9 until the final step (shown in Figure 7) of compressing the lithium receiving vessel. In such cases, the process comprises the utilization of the part 19 and in particular, the half-members 22 and 23, wherein the cathode assembly 25 is positioned between the half-members.

After the cathode assembly 25 has been positioned between said members as shown in Figure 3, preferably with anode lead 30 attached to lead 26, the lithium sheet is stamped around half-members 22 and 23 in a owner similar to that shown in Figure 9 The steps represented by Figures 4 to 7 Wd thR related description apply to this ~ tgod. Utilization of mould 9 is thereby deferred until the final step of cold welding the lithium folds.

As shown in Figure 8, the completed vessel 40 includes a fixed end 41 having a shape defined by end 11 of cavity 10, and an open end 42. The length of vessel 40, from end 41 to end 42, is determined by the length of stock sheet 15 used, as well as the length of half-members 22 and 23.

As can be seen, however, the length of the vessel formed may be varied greatly within the limits of the half-members, which would include most commercially useful sizes.

Referring to Figure 11, the receiving vessel 40 is filled with cathode material 43 through open end 42. Cathode material 43 is a charge-transfer complex of organic material and iodine. Charge-transfer complexes are a well-known class of materials that have two components, one an electron donor, and the other an electron acceptor, which form weakly bonded complexes that exhibit electronic conductivity higher than either component. The charge-transfer complexes are in chemical equilibrium with small amounts of free iodine that is available for electrochemical reaction. Cath- odes containing intimate mixtures of lowconductivity complexes with powdered graphite or inert metal have high conductivities and can provide performance comparable to cells using high-conductivity complexes. Suitable charge complexes may be prepared using an organic donor component, such as polycyclic-aromatic compounds, e.g., pyrene, anthracene and the like, organic polymers, for example, polyethylene, polypropylene, polyvinyls, or heterocyclic compounds containing nitrogen or sulphur, e.g., phenothiazine, phenazine and the like. Preferably, the charge transfer complexes comprise a mixture of iodine and solid poly-2-vinyl pyridine I2 or poly-2-vinylquinoline 12.

The electrolyte, preferably lithium iodine, is formed in situ when the anode and cathode surfaces contact and the lithium reacts with iodine in the cathode to form a solid lithium-halide electrolyte layer which is in contact with both the anode and the cathode. Alternatively, the electrolyte can be formed by coating lithium iodine or another lithium halide on the lithium anode, which coating is formed by reaction of the lithium with iodine or other halogen.

The cathode material is heated to a temperature of between 200"F. and 225"F. to provide a flowable consistency. Receiving vessel 40 is then completely filled with the heated cathode material 43 and the electrolyte is formed in situ. The vessel is chilled, for example to between --130" and --65"F., to solidify the cathode material 43. A lid member 45 having a shape substantially the same as opening 42 is positioned on the solidified cathode material 43. Ends 46 and 47 are crimped down and over lid 44 as shown in Figure 12. The side walls are then folded over the crimped end members as shown in Figure 13.

The entire assembly is then positioned in a chilled die similar to mould 9 shown in Figure 1 and the top pressed while the cathode material 43 is in the solidified state.

This pressing cold welds the lid member 44 and the crimped end and side folds into a unified leak-proof assembly. This assembly is preferably encased in a film, about 0005 to 0-015 inches thick, of fluoroplastic such as "Halar" or "Teflon", which is a Registered Trade Mark. This filrn acts both as an electrical insulator and as an additional seal against cathode or depolarizer leakage.

As shown in Figure 14, a "Halar" reinforcing member 48 is cemented to vessel 40 and anode and cathode lead 26 and 30, respectively. Lead extensions 51 and 52 are welded to cathode lead 26 and anode lead 30, respectively. As can be seen from Figure 14 lead extensions 51 and 52 are preferably spaced above and parallel to lid 44. Reinforcing member 48 and leads 26 and 30 are then bent at a 90" angle to position the lead extensions substantially in the centre of the vessel, as shown in Figure 15. A cover plate 54 including terminal pins 56 and 57 is positioned above lid 44.

Terminal pins 56 and 57 extend through cover 54 and are securely positioned and sealed therein by means of glass seals 58 and 59, respectively. Cathode and anode leads are bent at a 900 angle and their re spective extension leads welded to pins 56 and 57, respectively, as shown in Figure 17.

An insulator plate 61, e.g., one of mica 003 inches thick, is positioned between the bottom cover 54 and extension 51 and 52.

Cylindrical spacer members 62 and 63 are positioned between insulator 61 and lid 44 of vessel 40. As shown in Figure 18, each spacer member, which is preferably made from a ceramic material, includes a slot 64 which encompasses the respective extension lead and associated terminal pin. Spacers 62 and 63 are cemented to the top of lid 44 and the bottom of insulator member 61 as shown in Figure 18.

The assembly, as shown in Figure 19, is positioned within an outer case member 65, preferably one made of stainless steel. The assembly provides a substantially compression fit, but is secured with cement. Once inserted within the case, the outer peripheral edge of case 65 is welded to top cover 54 to provide a hermetic seal for the entire battery assembly.

WHAT WE CLAIM IS: - 1. A method for making a lithium halide battery which comprises the steps of: - (A) forming a lithium anode receiving vessel having a cathode lead em bedded within the vessel by: - (i) folding a lithium sheet into the; form of a vessel having an open ing; (ii) positioning a cathode lead hav- ing insulation thereon within said vessel such that one end of the lead is within the vessel to serve as a cathode current cok lector and the other extends be tween at least two folds of the lithium sheet to the outside of the vessel; (liy) pressing the folds together to embed the cathode lead there- between and to form a vessel in which the cathode lead is ex posed within the vessel and-at the opening; (iv) mounting an anode lead so that it extends to the exterior of th.

vessel; (B) heating a cathode material to a flow-- able consistency; (C) filing said vessel less than full with said cathode material and chilling said vessel and material to solidify the material; and (D) while the material is in the ssidified- state, positioning within said opening a lithium lid member having a shape substantially the same as said open ing and crimping the lithium of the vessel extending beyond the unfilled portion over the lid member and applying pressure so as to cold bond the crimped portion to the lid to seal the cathode within the vessel.

2. A method- as claimed in Claim' -1', which includes the steps of: - (E) positioning a cover member having a pair of terminal pins in spaced-apart relationship to the lid by interposi tioning at least one insulating spacer and electrically connecting said anode and cathode each to a termi nal pin; and (F) positioning the vessel in a metal case case and hermetically sealing said cover member to the case to form a battery.

3. A method as claimed in Claim 1 or Claim 2, wherein the said vessel is formed using a mould and including the steps of positioning said lithium sheet so that it extends beyond each side of the mould by an amount greater than one-half the width of the mould, positioning one end of said cathode lead adjacent the centre of the mould so that it extends away from the length of the mould, folding one of the extensions of the lithium sheet over said mould and cathode, bending said cathode lead over and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (17)

**WARNING** start of CLMS field may overlap end of DESC **. solidified cathode material 43. Ends 46 and 47 are crimped down and over lid 44 as shown in Figure 12. The side walls are then folded over the crimped end members as shown in Figure 13. The entire assembly is then positioned in a chilled die similar to mould 9 shown in Figure 1 and the top pressed while the cathode material 43 is in the solidified state. This pressing cold welds the lid member 44 and the crimped end and side folds into a unified leak-proof assembly. This assembly is preferably encased in a film, about 0005 to 0-015 inches thick, of fluoroplastic such as "Halar" or "Teflon", which is a Registered Trade Mark. This filrn acts both as an electrical insulator and as an additional seal against cathode or depolarizer leakage. As shown in Figure 14, a "Halar" reinforcing member 48 is cemented to vessel 40 and anode and cathode lead 26 and 30, respectively. Lead extensions 51 and 52 are welded to cathode lead 26 and anode lead 30, respectively. As can be seen from Figure 14 lead extensions 51 and 52 are preferably spaced above and parallel to lid 44. Reinforcing member 48 and leads 26 and 30 are then bent at a 90" angle to position the lead extensions substantially in the centre of the vessel, as shown in Figure 15. A cover plate 54 including terminal pins 56 and 57 is positioned above lid 44. Terminal pins 56 and 57 extend through cover 54 and are securely positioned and sealed therein by means of glass seals 58 and 59, respectively. Cathode and anode leads are bent at a 900 angle and their re spective extension leads welded to pins 56 and 57, respectively, as shown in Figure 17. An insulator plate 61, e.g., one of mica 003 inches thick, is positioned between the bottom cover 54 and extension 51 and 52. Cylindrical spacer members 62 and 63 are positioned between insulator 61 and lid 44 of vessel 40. As shown in Figure 18, each spacer member, which is preferably made from a ceramic material, includes a slot 64 which encompasses the respective extension lead and associated terminal pin. Spacers 62 and 63 are cemented to the top of lid 44 and the bottom of insulator member 61 as shown in Figure 18. The assembly, as shown in Figure 19, is positioned within an outer case member 65, preferably one made of stainless steel. The assembly provides a substantially compression fit, but is secured with cement. Once inserted within the case, the outer peripheral edge of case 65 is welded to top cover 54 to provide a hermetic seal for the entire battery assembly. WHAT WE CLAIM IS: -

1. A method for making a lithium halide battery which comprises the steps of: - (A) forming a lithium anode receiving vessel having a cathode lead em bedded within the vessel by: - (i) folding a lithium sheet into the; form of a vessel having an open ing; (ii) positioning a cathode lead hav- ing insulation thereon within said vessel such that one end of the lead is within the vessel to serve as a cathode current cok lector and the other extends be tween at least two folds of the lithium sheet to the outside of the vessel; (liy) pressing the folds together to embed the cathode lead there- between and to form a vessel in which the cathode lead is ex posed within the vessel and-at the opening; (iv) mounting an anode lead so that it extends to the exterior of th.

vessel; (B) heating a cathode material to a flow-- able consistency; (C) filing said vessel less than full with said cathode material and chilling said vessel and material to solidify the material; and (D) while the material is in the ssidified- state, positioning within said opening a lithium lid member having a shape substantially the same as said open ing and crimping the lithium of the vessel extending beyond the unfilled portion over the lid member and applying pressure so as to cold bond the crimped portion to the lid to seal the cathode within the vessel.

2. A method- as claimed in Claim' -1', which includes the steps of: - (E) positioning a cover member having a pair of terminal pins in spaced-apart relationship to the lid by interposi tioning at least one insulating spacer and electrically connecting said anode and cathode each to a termi nal pin; and (F) positioning the vessel in a metal case case and hermetically sealing said cover member to the case to form a battery.

3. A method as claimed in Claim 1 or Claim 2, wherein the said vessel is formed using a mould and including the steps of positioning said lithium sheet so that it extends beyond each side of the mould by an amount greater than one-half the width of the mould, positioning one end of said cathode lead adjacent the centre of the mould so that it extends away from the length of the mould, folding one of the extensions of the lithium sheet over said mould and cathode, bending said cathode lead over and

onto this folded extension and folding the other extension of the lithium sheet over and onto said cathode lead and folded extension to form the said vessel with the cathode lead positioned therein.

4. A method of making a lithium halide cell or battery having a lithium anode receiving vessel and cathode connecting lead wherein the cathode lead is positioned so that it lies within the wall of the receiving vessel for a substantial portion of its length.

5. A method as claimed in Claim 1 for making a lithium halide cell substantially as herein described with reference to the accompanying drawings.

6. A method as claimed in Claim 4 for making a lithium halide cell substantially as herein described.

7. A lithium halide cell or battery which has been produced using a method as claimed in any of Claims 1 to 6.

8. A lithium halide cell or battery as claimed in Claim 7, wherein the cathode lead with its end serving as a cathode current collector which is positioned in the vessel by a nonconductive positioning frame before the cathode material is introduced into the vessel.

9. A lithium halide cell as claimed in Claim 7 or Claim 8, wherein the cathode material consists essentially of an organic charge transfer complex and a halogen.

10. A lithium halide cell as claimed in any of Claims 7 to 9, wherein the nonconductive frame is configured to the internal cross-sectional dimensions of the receiving vessel.

11. A lithium halide cell as claimed in any of Claims 7 to 10, which includes an anode current collector having an anode lead having an insulating coating, which lead is positioned on the external side of the anode receiving vessel.

12. A lithium halide cell as claimed in Claim 11, wherein the said anode current collector and a portion of its lead are embedded within the lithium of the anode receiving vessel.

13. A lithium halide cell as claimed in Claim 11 or Claim 12, wherein the said anode receiving vessel and current collector are encapsulated in an insulating film.

14. A lithium halide cell as claimed in Claim 13, wherein the insulating film is made of a fluoroplastic substance.

15. A lithium halide battery comprising a cell as claimed in any of Claims 7 to 14 and a metal case surrounding the anode receiving vessel.

16. A lithium halide battery as claimed in Claim 15, wherein the said anode receiving vessel and current collector are encamp sulated within an insulating film and the resulting encapsulated vessel is positioned within a metal case comprising an end member having a pair of hermetically sealed terminals, said cathode lead and anode lead being electrically connected to a respective one of said terminals.

17. A lithium halide battery as claimed in Claim 16, wherein a ceramic spacer is positioned between the said end member and the said vessel at the connection of each of said leads and terminals.