Functionalized separator and method for preparing the same, lithium metal battery and device comprising the same
The present application discloses a functionalized separator, a method for preparing the same, a lithium metal battery, and a device comprising the lithium metal battery. The functionalized separator comprises a porous substrate and a functional film layer provided on at least one side of the porous substrate, wherein the functional film layer comprises inorganic particles which are able to reversibly react with metal lithium to form a lithium alloy.
1 . A functionalized separator, comprising a porous substrate and a functional film layer provided on at least one surface of the porous substrate,
wherein the functional film layer comprises inorganic particles which are able to reversibly react with metal lithium to form a lithium alloy and has a thickness of from 1 μm to 5 μm, and wherein the inorganic particles are SiO and have a volume average particle size Dv50 of from 1 μm to 2 μm,
wherein at least part of surfaces of the inorganic particles is coated with a polymer coating layer, wherein the polymer coating layer comprises a group that is reversibly bonded with lithium ions, wherein the polymer coating layer has a thickness of from 5 nm to 10 nm, and wherein the coating layer comprises polyolefin acid containing an acid radical group, and the polyolefin acid comprises one or more of polyacrylic acid and polystyrene sulfonic acid, and
wherein the functional film layer further comprises a polymer ionic liquid, wherein the polymer ionic liquid comprises the structural units represented by Formula IV:
wherein l and m are 240.
2 . The functionalized separator according to claim 1 ,
wherein the group that is reversibly bonded with lithium ions comprises one or more of the acid radical group, an amino group, an imino group, a sulfhydryl group, and a polysulfide group (—S b —, b≥2), and further optionally, the acid radical group comprises one or more of carboxylic acid group, sulfonic acid group, sulfinic acid group, and phosphoric acid group.
3 . The functionalized separator according to claim 1 , wherein the polymer ionic liquid further comprises a structural unit represented by formula III:
wherein,
R 5 is C1-C10 alkylene group or C1-C10 alkylene group containing one or more of F, Cl, Br, I, N, O, S, Si, B, and P, and optionally is —(CH 2 ) t — or —(CH 2 ) q —O—(CH 2 ) r —, wherein t is from 1 to 8, q is from 0 to 4, r is from 0 to 4, and q and r are not 0 at the same time;
R 6 is H, F, Cl, Br, I, —CN, C1-C10 hydrocarbon group, or C1-C10 hydrocarbon group containing one or more of F, Cl, Br, I, N, O, S, Si, B and P, and optionally is H, —CN, —CH 3 , —C 2 H 5 , linear —C 3 H 7 , linear —C 4 H 9 , or —(CH 2 CH 2 O) u CH 3 wherein u is from 1 to 8;
n is a positive integer; optionally, 1≤n≤2500.
4 . The functionalized separator according to claim 1 , wherein polymer ionic liquid has a number average molecular weight of from 40,000 to 1,000,000.
5 . The functionalized separator according to claim 1 , wherein, in the functional film layer, the mass ratio of the inorganic particles to the polymer ionic liquid is (80-99):(1-20).
6 . The functionalized separator according to claim 1 , wherein the substrate is a polymer substrate; and
optionally, the substrate has a thickness of from 5 μm to 25 μm.
7 . A lithium metal battery, comprising
a positive electrode plate;
a negative electrode plate comprising a lithium-based metal layer;
a separator which is the functionalized separator according to claim 1 , wherein the functional film layer is arranged to contact with the lithium-based metal layer; and
an electrolyte solution.
8 . A device comprising the lithium metal battery according to claim 7 .
9 . The functionalized separator according to claim 1 , comprising a porous substrate and a functional film layer provided on at least one surface of the porous substrate,
wherein the functional film layer comprises inorganic particles which are able to reversibly react with metal lithium to form a lithium alloy and has a thickness of 5 μm, and wherein the inorganic particles are SiO and have a volume average particle size Dv50 of from 1 μm to 2 μm,
wherein at least part of surfaces of the inorganic particles is coated with a polymer coating layer, wherein the polymer coating layer comprises a group that is reversibly bonded with lithium ions, wherein the polymer coating layer has a thickness of 10 nm, and wherein the coating layer comprises polyolefin acid containing an acid radical group, and the polyolefin acid comprises one or more of polyacrylic acid and polystyrene sulfonic acid, and
wherein the functional film layer further comprises a polymer ionic liquid, wherein the polymer ionic liquid comprises the structural units represented by Formula IV:
wherein l and m are 240.