Storage battery

Patent metadata

Field	Value
Publication number	US-12224435-B2
Application number	US-202217580529-A
Country	US
Kind code	B2
Filing date	Jan 20, 2022
Priority date	Jul 22, 2020
Publication date	Feb 11, 2025
Grant date	Feb 11, 2025

Abstract

According to a storage battery of an embodiment includes a first battery module and a second battery module connected in parallel with the first battery module. The number of first cells connected in series in the first battery module is M, and the number of second cells connected in series in the second battery module is N. When an open circuit voltage at SOC=X % of the first cells and the second cells are Va1 (X) and Va2 (X), respectively, the voltages of the battery modules are M×Va1 (X)<N×Va2 (X) in the range where the SOC of the cell is 0% to 30%, and M×Va1 (X)>N×Va2 (X) in the range where the SOC of the cell is 70% to 100%.

First claim

What is claimed is:

1. A storage battery comprising:
a first battery module including a plurality of first cells connected in series, each of the plurality of first cells containing titanium composite oxide as a negative electrode active material; and
a second battery module including a plurality of second cells connected in series, each of the plurality of second cells containing a carbonaceous material as a negative electrode active material, the second battery module being connected in parallel with the first battery module,
wherein
a voltage of the storage battery is changeable between a lower limit voltage value and an upper limit voltage value,
at the lower limit voltage value of the storage battery, an SOC of the second battery module is lower than an SOC of the first battery module, and a resistance of the second battery module is higher than a resistance of the first battery module,
at the upper limit voltage value of the storage battery, the SOC of the second battery module is higher than the SOC of the first battery module, and the resistance of the second battery module is higher than the resistance of the first battery module, and
the first battery module and the second battery module satisfy the following formulas (1) and (2):

M
×
Va
⁢

⁢
1
⁢

(
X
)

<

N
×
Va
⁢

⁢
2
⁢

(
X
)

⁢

(

0
≦
X
≦
30

)

;
and

(
1
)

M
×
Va
⁢

⁢
1
⁢

(
X
)

>

N
×
Va
⁢

⁢
2
⁢

(
X
)

⁢

(

70
≦
X
≦
100

)

,

(
2
)

wherein Va 1 (X) represents an open circuit voltage at SOC=X % of each of the plurality of first cells, Va 2 (X) represents an open circuit voltage at SOC=X % of each of the plurality of second cells, M represents the number of the plurality of first cells connected in series in the first battery module, and N represents the number of the plurality of second cells connected in series in the second battery module.

2. The storage battery according to claim 1 , wherein
each of the plurality of first cells contains monoclinic niobium titanium composite oxide as the negative electrode active material,
each of the plurality of second cells contains graphite as the negative electrode active material, and
the first battery module and the second battery module satisfy the following formulas (3) and (4):

M
×
1.88

<

N
×
3.47

;
and

(
3
)

M
×
2.68

>

N
×

4.05
.

(
4
)

Assignees

• Toshiba Kk

Inventors

• Yagi Ryosuke
• Harada Yasuhiro
• Takami Norio
• Sasakawa Tetsuya
• Yoshinaga Norihiro
• Kanai Yuta

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title