Pressurized lithium metal polymer battery
A lithium metal polymer battery comprising a rigid casing and at least one electrochemical cell; the battery assembled without an active mechanical pressure system.
1. A lithium metal polymer battery comprising:
a rigid casing having a first wall and a second wall opposite the first wall; and
a plurality of electrochemical cells stacked in the rigid casing between the first and second walls,
each electrochemical cell of the plurality of electrochemical cells comprising:
an anode made of lithium or lithium alloy metallic sheet,
a cathode made of an active material comprising olivine, spinel or layered structure in their lithiated state, and
a solid polymer electrolyte disposed between the anode and the cathode,
the plurality of electrochemical cells having a first thickness in a first state of the plurality of electrochemical cells whereby the first and second walls exert a first pressure on the plurality of electrochemical cells,
the plurality of electrochemical cells having a second thickness in a second state of the plurality of electrochemical cells whereby the first and second walls exert a second pressure on the plurality of electrochemical cells,
the second thickness being greater than the first thickness,
the second pressure being greater than the first pressure,
the first state being a discharged state,
the second state being at least one of a charged state and a heated state where the plurality of electrochemical cells is thermally expanded, and
the battery being free of an active mechanical pressure system.
2. A lithium metal polymer battery as defined in claim 1 , wherein the electrochemical cells are assembled in a flat wound prismatic configuration.
3. A lithium metal polymer battery as defined in claim 1 , further comprising a layer of elastic material positioned between the rigid casing and the plurality of electrochemical cells.
4. A lithium metal polymer battery as defined in claim 1 , wherein the first wall is a lower wall of the rigid casing and the second wall is an upper wall of the rigid casing.
5. A lithium metal polymer battery as defined in claim 1 , wherein in the heated state the plurality of electrochemical cells initially has a temperature between 60° C. and 80° C.
6. A lithium metal polymer battery as defined in claim 1 , wherein in the second state a volume of the plurality of electrochemical cells is at least 3% higher than in the first state.
7. A lithium metal polymer battery as defined in claim 1 , wherein the first pressure is greater than zero.
8. A lithium metal polymer battery as defined in claim 1 , wherein the second pressure is at least 20 psi.
9. A lithium metal polymer battery as defined in claim 1 , wherein the second pressure is between 400 and 800 psi.
10. A lithium metal polymer battery as defined in claim 1 , wherein the second state is the charged state.
11. A lithium metal polymer battery as defined in claim 10 , wherein the second state is the charged state and the heated state.