US 2013/0230765 A1Published application

Current collector copper foil of negative electrode for lithium ion secondary battery, method of manufactuing the current collector copper foil of negative electrode for lithium ion secondary battery, negative electrode for lithium ion secondary battery, method of manufacturing negative electrode for lithium ion secondary battery, and lithium ion secondary battery

AssigneeHitachi Cable, Ltd.

InventorsYoshiki SAWAI, Satoshi SEKI

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Abstract

There is provided a current collector copper foil of negative electrode for lithium ion secondary battery, including: at least 0.15 wt % or more and 0.40 wt % or less of Cr; and Cu as a remaining portion, wherein a Cr solid solution index Z is in a range of 0.05≦Z≦0.3 and represented by the following formula: Z=(RM−RS)/(RP−RS) . . . (1), wherein RM indicates an actually measured conductivity R (% IACS) of a negative battery current collector copper foil, and RS indicates a calculated value (% IACS) of conductivity R of the negative electrode current collector copper foil 10 in a case that a total content of Cr is solid-soluted, and conductivity RP indicates a calculated conductivity R (% IACS) of the negative electrode current collector copper foil 10 in a case that the total content of Cr is separated.

A current collector copper foil of negative electrode for lithium ion secondary battery, comprising:

at least 0.15 wt % or more and 0.40 wt % or less of Cr;
and
Cu as a remaining portion,
wherein a Cr solid solution index Z is in a range of 0.05≦Z≦0.3 and represented by the following formula (1),
[
Formula


1
]
Z
=
(
R
M
-
R
S
)
(
R
P
-
R
S
)
(
1
)
wherein in the formula (1), conductivity RM indicates an actually measured conductivity R (% IACS) of the current collector copper foil of negative electrode for lithium ion secondary battery, and conductivity RS indicates a calculated conductivity R (% IACS) of the current collector copper foil of negative electrode for lithium ion secondary battery, which is the conductivity R (% IACS) defined by the following formula (3) from electric resistivity ρ obtained by substituting a content concentration [atomic %] of each alloy element in a solid-soluted state when a total content of the Cr is solid-soluted, into the following formula (2), and conductivity RP indicates a calculated conductivity R (% IACS) of the lithium ion secondary negative electrode current collector copper foil, which is the conductivity R (% IACS) defined by the following formula (3) from electric resistivity ρ obtained by substituting a content concentration [atomic %] (at %) of each alloy element in a solid-soluted state when a total content of the Cr is separated, into the following formula (2),

[
Formula


2
]
ρ
=
17.241
+
(
40
×
Cr


concentration

[
at


%
]
+
1.2
×
Ag


concentration

[
at


%
]
+
28.8
×
Sn


concentration

[
at


%
]
+
10.5
×
In


concentration

[
at


%
]
+
116.1
×
Ti


concentration

[
at


%
]
+
110
×
Zr


concentration

[
at


%
]
)
-
(
3.2
×
28.8
×
Sn


concentration

[
at


%
]
2
+
2.4
×
10.5
×
In


concentration

[
at


%
]
2
+
116.1
×
Ti


concentration

[
at


%
]
2
)
/
100
(
2
)

[
Formula


3
]

R
=
(
17.241
ρ
)
×
100
(
3
)

198 more elements

Abstract

Claims10