Anode and secondary battery
View Patent ↗A secondary battery capable of improving the cycle characteristics and the swollenness characteristics is provided. The secondary battery includes a cathode, an anode, and an electrolytic solution. The anode includes an anode active material layer having a plurality of fine pores on an anode current collector. The anode active material layer contains an anode active material and an anode binder. A change rate of a mercury intrusion into the plurality of fine pores measured by mercury penetration technique is distributed to show a peak in the pore diameter range from 30 nm to 10000 nm, both inclusive.
1. A secondary battery comprising:
a cathode;
an anode; and
an electrolytic solution,
wherein,
the anode includes an anode collector and an anode active material layer on the anode current collector,
the anode active material layer comprises an anode active material and an anode binder,
the anode active material layer comprises a plurality of fine pores therein,
the anode active material layer has a distribution of a change rate of a mercury intrusion into the plurality of fine pores measured by mercury penetration technique showing a maximum peak in a pore diameter range from and including 1,000 nm to 5,000 nm and
a porosity of the anode active material layer is in the range from and including 4% to 70%.
2. The secondary battery according to claim 1 , wherein the change rate of the mercury intrusion into the plurality of fine pores shows a plurality of peaks, and a maximum peak among the peaks exists in a pore diameter range from and including 2,000 nm to 5000 nm.
3. The secondary battery according to claim 1 , wherein the anode active material is in a state of a plurality of particles, and a median size thereof is in the range from and including 0.5 μm to 20 μm.
4. The secondary battery according to claim 1 , wherein the anode active material is at least one selected from the group consisting of a simple substance of silicon, an alloy of silicon, and a compound of silicon.
5. The secondary battery according to claim 1 , wherein the anode active material layer is formed by at least one of coating method and sintering method.
6. The secondary battery according to claim 1 , wherein the anode binder is at least one selected from the group consisting of polyimide, polyamide, and polyamideimide.
7. The secondary battery according to claim 6 , wherein at least part of the anode binder is carbonized.
8. The secondary battery according to claim 1 , wherein ten point height of roughness profile Rz of a surface of the anode current collector is in the range from and including 0.5 μm to 6.5 μm.
9. The secondary battery according to claim 1 , wherein the electrolytic solution contains a solvent containing at least one of a chain ester carbonate having halogen represented by Chemical formula 1, a cyclic ester carbonate having halogen represented by Chemical formula 2, a cyclic ester carbonate having an unsaturated bond represented by Chemical formula 3 to Chemical formula 5, sultone, and an acid anhydride chemical formula 1-5 being:
where each of R11 to R16 represent a hydrogen group, a halogen group, an alkyl group, or an alkyl halide group, and at least one of R11 to R16 is the halogen group or the alkyl halide group,
where each of R17 to R20 represent a hydrogen group, a halogen group, an alkyl group, or an alkyl halide group, and at least one of R17 to R20 is the halogen group or the alkyl halide group,
where each of R21 and R22 represent a hydrogen group or an alkyl group,
where each of R23 to R26 represent a hydrogen group, an alkyl group, a vinyl group, or an aryl group, and at least one of R23 to R26 represents the vinyl group or the aryl group, and
where R27 represent an alkylene group.
10. The secondary battery according to claim 9 , wherein (a) the chain ester carbonate having halogen represented by the Chemical formula 1 is fluoromethyl methyl carbonate, bis(fluoromethyl) carbonate, or difluoromethyl methyl carbonate, (b) the cyclic ester carbonate having halogen represented by the Chemical formula 2 is 4-fluoro-1,3-dioxolane-2-one or 4,5-difluoro-1,3-dioxolane-2-one, (c) the cyclic ester carbonate having an unsaturated bond represented by the Chemical formula 3 is vinylene carbonate, (d) the cyclic ester carbonate having an unsaturated bond represented by the Chemical formula 4 is vinylethylene carbonate, and (d) the cyclic ester carbonate having an unsaturated bond represented by the Chemical formula 5 is methylene ethylene carbonate.
11. The secondary battery according to claim 1 , wherein the electrolytic solution contains an electrolyte salt containing at least one selected from the group consisting of lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), the compounds represented by Chemical formula 6 to Chemical formula 8, and the compounds represented by Chemical formula 9 to Chemical formula 11, chemical formulae 6-11 being:
where (a) X31 represents a Group 1 element or a Group 2 element in the long period periodic table or aluminum (Al), (b) M31 represents a transition metal element, a Group 13 element, a Group 14 element, or a Group 15 element in the long period periodic table, (c) R31 represents a halogen group, (d) Y31 represents —(O═)C—R32—C(═O)—, —(O═)C—C(R33) 2 —, or —(O═)C—C(═O)—, (e) R32 represents an alkylene group, an alkylene halide group, an arylene group, or an arylene halide group, (f) R33 represents an alkyl group, an alkyl halide group, an aryl group, or an aryl halide group, (g) a3 represents one of integer numbers 1 to 4, b3 represents 0, 2, or 4, and c3, d3, m3, and n3 each represent one of integer numbers 1 to 3,
where (a) X41 represents a Group 1 element or a Group 2 element in the long period periodic table, (b) M41 represents a transition metal element, a Group 13 element, a Group 14 element, or a Group 15 element in the long period periodic table, (c) Y41 represents —(O═)C—(C(R41) 2 ) b4 -C(═O)—, —(R43) 2 C—(C(R42) 2 ) c4 -C(═O)—, —(R43) 2 C—(C(R42) 2 ) c4 -C(R43) 2 -, —(R43) 2 C—(C(R42) 2 ) c4 -S(═O) 2 —, —(O═) 2 S—(C(R42) 2 ) d4 -S(═O) 2 —, or —(O═)C—(C(R42) 2 ) d4 -S(═O) 2 —, (d) each of R41 and R43 represent a hydrogen group, an alkyl group, a halogen group, or an alkyl halide group, (e) at least one of R41 and/or R43 represents the halogen group or the alkyl halide group, (f) R42 represents a hydrogen group, an alkyl group, a halogen group, or an alkyl halide group, (g) each of a4, e4, and n4 represent 1 or 2, each of b4 and d4 represent one of integer numbers 1 to 4, c4 represents one of integer numbers 0 to 4, and each of f4 and m4 represent one of integer numbers 1 to 3,
where (a) X51 represents a Group 1 element or a Group 2 element in the long period periodic table, (b) M51 represents a transition metal element, a Group 13 element, a Group 14 element, or a Group 15 element in the long period periodic table, (c) Rf represents a fluorinated alkyl group with the carbon number in the range from and including 1 to 10, or a fluorinated aryl group with the carbon number in the range from and including 1 to 10, (d) Y51 represents —(O═)C—(C(R51) 2 ) d5 -C(═O)—, —(R52) 2 C—(C(R51) 2 ) d5 -C(═O)—, —(R52) 2 C—(C(R51) 2 ) d5 -C(R52) 2 -, -(R52) 2 C—(C(R51) 2 ) d5 —S(═O) 2 -, —(O═) 2 S—(C(R51) 2 ) e5 -S (═O) 2 -, or —(O═)C —(C(R51) 2 ) e5 —S (═O) 2 —, (e) R51 represents a hydrogen group, an alkyl group, a halogen group, or an alkyl halide group, (f) R52 represents a hydrogen group, an alkyl group, a halogen group, or an alkyl halide group, and at least one thereof is the halogen group or the alkyl halide group, (g) each of a5, f5, and n5 represent 1 or 2, each of b5, c5, and e5 represent one of integer numbers 1 to 4, d5 represents one of integer numbers 0 to 4, and each of g5 and m5 represent one of integer numbers 1 to 3, and
LiN(C m F 2m+1 SO 2 )(C n F 2n+1 SO 2 ) Chemical formula 9
where each of m and n represent an integer number of 1 or more,
where R61 represents a straight chain or branched perfluoro alkylene group with the carbon number in the range from and including 2 to 4,
LiC(C p F 2p+1 SO 2 )(C q F 2q+1 SO 2 )(C r F 2r+1 SO 2 )Chemical formula 11
where each of p, q, and r represent an integer number of 1 or more.
12. The secondary battery according to claim 11 , wherein (a) the compound represented by the Chemical formula 6 is a compound represented by Chemical formulas 12(1) to 12(6), (b) the compound represented by the Chemical formula 7 is a compound represented by Chemical formulas 13(1) to 13(8), and (c) the compound represented by the Chemical formula 8 is a compound represented by Chemical formula 14 chemical formulae 12(1) to 12(6), 13(1) to 13(8) and 14 being:
13. The secondary battery according to claim 1 , wherein an anode utilization in the full charge state of the anode is in the range from and including 20% to 80%.
14. The secondary battery according to claim 1 , wherein the cathode, the anode, and the electrolytic solution are contained in a cylindrical or square package member.
15. The secondary battery according to claim 14 , wherein the package member contains iron or an iron alloy.
16. An anode comprising:
a current collector; and
an anode active material layer on the current collector,
wherein,
the anode active material layer comprises an anode active material and an anode binder,
the anode active material layer comprises a plurality of fine pores therein,
the anode active material layer has a distribution of a change rate of a mercury intrusion into the plurality of fine pores measured by mercury penetration technique showing a peak in a pore diameter range from and including 100 nm to 5,000 nm, and
a porosity of the anode active material layer is in the range from and including 4% to 70%.