Battery stack casing
A battery cell stack casing includes casing walls defining a housing interior for receiving a battery cell stack; a first end plate provided between the walls at a first end of the casing to close a first end of the housing interior. The casing also include a second end plate provided between the walls at a second end of the casing to close a second end of the housing interior. The casing walls have a multi-layer structure include: an inner layer having a first side facing into the housing interior and a second opposite side; an outer layer spaced outwardly from the second side of the inner layer; a thermally insulating volume defined between the second side of the inner layer and the outer layer, the thermally insulating material containing a low density thermally insulative material e.g., foam or other insulative material; and a layer of intumescent material provided on the first side of the inner layer.
1 . A battery cell stack casing comprising:
casing walls defining a housing interior for receiving a battery cell stack;
a first end plate provided between the walls at a first end of the casing to close a first end of the housing interior; and
a second end plate provided between the walls at a second end of the casing to close a second end of the housing interior;
wherein the casing walls have a multi-layer structure comprising:
an inner layer having a first side facing into the housing interior and a second opposite side;
an outer layer spaced outwardly from the second side of the inner layer;
a thermally insulating volume defined between the second side of the inner layer and the outer layer, the thermally insulating volume being provided with a foam;
a layer of intumescent material provided on the first side of the inner layer; and
an insert fitted between and directly adjacent to the inner and outer layers at the ends of the casing walls adjacent the end plates.
2 . The casing of claim 1 , wherein the insert provides a groove for a seal at the interface between the foam and the inner and outer layers.
3 . The casing of claim 2 , wherein the groove has a female radial dovetail form with a rectangular cross-section.
4 . The casing of claim 2 , wherein a seal is mounted in the groove.
5 . The casing of claim 4 , wherein the seal is an elastomeric seal.
6 . The casing of claim 4 , wherein the seal is an adhesive bead.
7 . The casing of claim 1 , wherein the insert is a polymer insert.
8 . The casing of claim 1 , wherein the foam is a closed-cell foam.
9 . The casing of claim 1 , wherein the first and second end plates have a multi-layer structure comprising:
an inner layer having a first side facing into the housing interior and a second opposite side;
an outer layer spaced outwardly from the second side of the inner layer;
a thermally insulating volume defined between the second side of the inner layer and the outer layer; and
a layer of intumescent material provided on the first side of the inner layer.
10 . The casing of any preceding claim , wherein the inner and outer layers comprise carbon fiber reinforced polymer (CFRP).
11 . A battery unit comprising:
a casing as claimed in claim 1 ; and
a stack of battery cells mounted in the casing.
12 . A battery unit as claimed in claim 10 , wherein the battery cells are lithium ion cells.