JP6112225B2 - Control valve type lead acid battery - Google Patents

Description

  The present invention relates to a valve-regulated lead-acid battery used in a partially charged state.

  Generally, a valve-regulated lead acid battery is used as a lead acid battery used for power storage and system power leveling such as wind power and solar power generation. This control valve type lead-acid battery is always required to be able to be used under severe usage conditions such as being kept in an undercharged state called partial state of charge (PSOC) and being charged and discharged with a large current. Has been. However, if charging / discharging is repeated in the PSOC state, a crystal of lead sulfate, which is a discharge material, grows and coarsens on the negative electrode, and a problem (sulfation) in which reversibility is lost occurs. On the other hand, the following Patent Document 1 (Japanese Patent Laid-Open No. 2003-123760) discloses a lead obtained by adding carbon black (acetylene black) to a negative electrode active material as a negative electrode of a lead storage battery used in a PSOC state. A technique using a negative electrode for a storage battery is disclosed.

JP 2003-123760 A

  However, the lead storage battery described in Patent Document 1 is intended for automotive applications, and has sufficient cycle characteristics when applied to a lead storage battery used for storage of natural energy and leveling of system power. This is not clear from the results of the study by the present inventors.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control valve type lead storage battery having excellent cycle characteristics in a control valve type lead storage battery operated in a partially charged state.

Valve-regulated lead-acid battery to which the present invention is directed to improvements are valve-regulated lead-acid battery comprising a negative electrode plate including a negative electrode active material and carbon black. The negative electrode plate contains graphite in addition to carbon black. The graphite used in the present invention is graphite having an average particle size of 90 μm or less and a DBP oil absorption of 55 ml / 100 g or more. And graphite content is 0.5-5.0 mass% with respect to 100 mass% of negative electrode active materials, and content of carbon black is 0.1-5. 0% by mass.

  Here, “average particle diameter” means a particle diameter (D50) at which the volume-based cumulative distribution measured by the laser diffraction / scattering method is 50%. Further, “DBP oil absorption” is the oil absorption determined by the oil absorption B method (the spatula kneading method) described in JIS K-6221 (1982). In addition, the high DBP oil absorption of graphite generally indicates that the crystallinity of graphite is high.

  When graphite having such an average particle diameter and DBP oil absorption is added to the negative electrode active material together with carbon black, the cycle characteristics are improved while maintaining the initial capacity even in the case of a lead storage battery used in the PSOC state. That is, by providing a negative electrode plate using a negative electrode active material containing graphite having a small average particle size and high crystallinity (the layered structure is not destroyed) together with carbon black, a cycle higher than the conventional one is provided. A control valve type lead storage battery exhibiting characteristics can be obtained.

  In addition, if it is graphite with a small average particle diameter and high crystallinity, the lower limit of the average particle diameter of graphite and the upper limit of the DBP oil absorption amount are not limited. However, considering the availability of graphite material, the lower limit of the average particle diameter of graphite is about 1 μm, and the upper limit of DBP oil absorption of graphite is considered to be about 300 ml / 100 g.

  The graphite added to the negative electrode active material is preferably graphite having an average particle diameter of 1 μm to 60 μm and a DBP oil absorption of 65 ml / 100 g or more. When graphite having such an average particle size and DBP oil absorption in such a numerical range is used, not only the cycle characteristics are improved, but also the initial capacity can be improved.

  Further, it is more preferable that the graphite has an average particle size of 1 μm to 20 μm and a DBP oil absorption of 85 ml / 100 g or more. When graphite having such an average particle diameter and DBP oil absorption in such a numerical range is used, the cycle characteristics are remarkably improved while maintaining or improving the initial capacity.

  The graphite content is preferably 0.5 to 3.0% by mass with respect to 100% by mass of the negative electrode active material. When the graphite content is adjusted to such a numerical range, a control valve type lead-acid battery with improved initial capacity and cycle characteristics can be obtained with certainty.

  More preferably, the graphite content is 1.0 to 3.0% by mass with respect to 100% by mass of the negative electrode active material. By adjusting the graphite content to such a numerical range, it is possible to reliably obtain a control valve type lead-acid battery whose cycle characteristics are remarkably improved while maintaining or improving the initial capacity.

  On the other hand, the carbon black content is preferably adjusted to 0.3 to 3.0% by mass with respect to 100% by mass of the negative electrode active material. When the carbon black content is adjusted to such a numerical range, a control valve type lead-acid battery with improved initial capacity and cycle characteristics can be obtained even when the graphite content is relatively low.

  More preferably, the carbon black content is adjusted to 1.5 to 3.0% by mass with respect to 100% by mass of the negative electrode active material. By adjusting the carbon black content to such a numerical range, a control valve type lead storage battery in which the cycle characteristics are significantly improved while maintaining or improving the initial capacity even when the graphite content is relatively small is obtained. be able to.

  Examples of carbon black added to the negative electrode active material include acetylene black, furnace black, channel black, thermal black, and ketjen black. Among these, when acetylene black is used, cycle characteristics can be improved as compared with the case where carbon black other than acetylene black is used.

  Hereinafter, embodiments of the present invention will be described in detail. The control valve type lead storage battery of this example can be manufactured as follows, for example.

(Negative electrode plate)
First, the negative electrode active material is composed of at least carbon black (acetylene black) and graphite having an average particle size of 90 μm or less and a DBP oil absorption of 55 ml / 100 g or more with respect to lead powder containing lead monoxide as a main component. Added. In addition, a kneaded mixture is prepared by adding barium sulfate, reinforcing short fibers (acrylic fiber, polypropylene fiber, polyethylene terephthalate fiber, etc.) and the like as necessary. Water and sodium lignin sulfonate are added to the mixture and mixed, and further dilute sulfuric acid is added to prepare a negative electrode active material paste.

  The content of acetylene black added as carbon black is preferably 0.1 to 5.0% by mass with respect to 100% by mass of the negative electrode active material from the viewpoint of improving cycle characteristics while maintaining at least the initial capacity. . In consideration of improving not only the cycle characteristics but also the initial capacity, the content is preferably 0.1 to 3.0% by mass with respect to 100% by mass of the negative electrode active material. Further, in order to improve the initial capacity and obtain high cycle characteristics, the content is preferably 1.5 to 3.0% by mass with respect to 100% by mass of the negative electrode active material.

  The content of graphite may be 0.5 to 5% by mass with respect to 100% by mass of the negative electrode active material in consideration of improving the cycle characteristics while maintaining at least the initial capacity. In consideration of improving not only the cycle characteristics but also the initial capacity, the content is preferably 0.5 to 3.0% by mass with respect to 100% by mass of the negative electrode active material. Further, in order to improve the initial capacity and obtain high cycle characteristics, the content is more preferably 1.0 to 3.0% by mass with respect to 100% by mass of the negative electrode active material.

  The DBP oil absorption of graphite can be determined by the above-described spatula kneading method.

  The average particle diameter of graphite may be 90 μm or less as described above from the viewpoint of improving cycle characteristics while maintaining at least the initial capacity. Further, from the viewpoint of improving not only the cycle characteristics but also the initial capacity, 1 μm to 60 μm is preferable, and from the viewpoint of improving the initial capacity and further improving the cycle characteristics, 1 μm to 20 μm is more preferable. In addition, an average particle diameter is calculated | required as the above-mentioned particle diameter (D50).

  Further, the DBP oil absorption amount of graphite may be 55 ml / 100 g or more as described above from the viewpoint of improving the cycle characteristics while maintaining at least the initial capacity. Moreover, from the viewpoint of improving not only the cycle characteristics but also the initial capacity, it is preferably 65 ml / 100 g or more, and from the viewpoint of improving the initial capacity and further improving the cycle characteristics, it is 85 ml / 100 g or more. Is more preferable. Note that the upper limit of the DBP oil absorption amount is not limited, but may be 500 ml / 100 g or less from a practical viewpoint, and may be 300 ml / 100 g or less in practice.

  In order to further improve the discharge characteristics, sodium lignin sulfonate may be added. When sodium lignin sulfonate is included, the content thereof is preferably 0.05 to 1% by mass, more preferably 0.1 to 0.8% by mass, and more preferably 0.2 to 0% with respect to 100% by mass of the negative electrode active material. More preferably, 6% by mass.

  When the reinforcing short fibers are included, the content thereof is preferably 0.01 to 0.3% by mass and more preferably 0.02 to 0.1% by mass with respect to 100% by mass of the negative electrode active material.

  When barium sulfate is used, the content is preferably 0.01 to 2% by mass and more preferably 0.1 to 1.5% by mass with respect to 100% by mass of the negative electrode active material.

  Next, the negative electrode active material paste produced as described above is filled in a current collector grid, aged, and then dried to produce an unformed negative electrode plate.

  The current collector grid is composed of a lead-calcium-tin alloy, a lead-calcium alloy, or a lead-calcium-tin alloy or a lead-calcium alloy in which a small amount of arsenic, selenium, silver, or bismuth is added thereto. Can be used.

  The aging conditions are preferably 40 to 60 hours in an atmosphere at a temperature of 35 to 85 ° C. and a humidity of 50 to 90%. The drying conditions are preferably 15 to 30 hours at a temperature of 50 to 80 ° C.

(Positive electrode plate)
The positive electrode plate can be obtained, for example, by the following method. First, after adding a reinforcing short fiber to lead powder containing lead monoxide as a main component, water and dilute sulfuric acid are added. This is kneaded to prepare a positive electrode active material paste. In producing the positive electrode active material paste, red lead (Pb ₃ O ₄ ) may be added. After filling this positive electrode active material paste into a current collector (current collector grid or the like), aging and drying are performed to obtain an unformed positive electrode. In the positive electrode active material paste, the content of the reinforcing short fibers is preferably 0.005 to 0.3% by mass based on the total mass of the positive electrode active material. The type of collector grid, aging conditions, and drying conditions are almost the same as in the case of the negative electrode.

(Assembly of control valve type lead acid battery)
In the assembly process, for example, the negative electrode and the positive electrode manufactured as described above are stacked via a retainer (separator), and the electrode plates having the same polarity are connected to each other with a strap to obtain the electrode plate group. This electrode group is arranged in a battery case to produce an unformed battery. Next, dilute sulfuric acid is added to the non-chemical cell to perform chemical conversion treatment. Subsequently, after removing the diluted sulfuric acid once, a lead storage battery is obtained by adding an electrolytic solution (dilute sulfuric acid). The specific gravity (converted to 20 ° C.) of dilute sulfuric acid is preferably 1.25 to 1.35. The material of the battery case is not particularly limited, and specifically, polypropylene, ABS, modified PPE (polyphenylene ether) or the like can be used.

  The lid is not particularly limited as long as it closes the opening of the battery case described above, and the same or different material can be used for the lid. However, it is preferable to use a material having the same thermal expansion coefficient so that the lid body does not fall off due to deformation when heated.

  The control valve is for discharging excess gas that could not be absorbed by the gas absorption reaction of the negative electrode out of the oxygen tank generated during charging. As the material, it is preferable to use a material excellent in chemical resistance (acid resistance, silicon oil resistance), wear resistance, and heat resistance, specifically, fluororubber.

  A glass fiber etc. are mentioned as a material of a retainer (separator). The chemical conversion conditions and the specific gravity of dilute sulfuric acid can be adjusted according to the size of the electrode. The chemical conversion treatment is not limited to being performed in the assembly process, and may be performed in the electrode manufacturing process.

  Hereinafter, the examples used in this example will be described in detail.

Example 1
<Preparation of negative electrode plate>
Acetylene black (trade name: Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) 1.5 mass% and graphite (trade name: UP-5, manufactured by Nippon Graphite Industry Co., Ltd., average grain) with respect to 100% by mass of lead powder Diameter: 5 μm, DBP oil absorption: 220 ml / 100 g) 2% by mass, barium sulfate 1% by mass, polyethylene terephthalate fiber (PET fiber) 0.03% by mass, sodium lignin sulfonate (trade name: Vanillex N, Japan After adding 0.5% by mass (manufactured by Paper Manufacturing Co., Ltd.), dry mixing was performed. Next, it knead | mixes, adding dilute sulfuric acid (specific gravity 1.26 / 20 degreeC conversion) and water, and produced the negative electrode active material paste. On the other hand, a lead-calcium-tin alloy was melted and cast to prepare a current collector grid having a length of 131.0 mm, a width of 116.0 mm, and a thickness of 2.5 mm. After this current collector grid was filled with the prepared negative electrode active material paste, a negative electrode plate was produced under the following aging and drying conditions.

Aging condition: temperature: 40 ° C., humidity: 98%, time: 40 hours Drying condition: temperature: 60 ° C., time: 24 hours The oil absorption of graphite is dibutyl phthalate (DBP) by a spatula kneading method. Was dropped into graphite in small portions, and the amount of DBP dropped when the entire graphite sample was agglomerated was measured. Moreover, the average particle diameter (D50) of graphite was measured by the method described in JIS R1629.

<Preparation of positive electrode plate>
Based on the total mass of the lead powder, a cut fiber made of 0.15% by mass of polyethylene fiber and 6% by mass of red lead were added to the lead powder and then dry mixed. Next, dilute sulfuric acid (specific gravity 1.26 / 20 ° C conversion) and water were added and kneaded to prepare a positive electrode active material paste. A lead-calcium-tin alloy was melted and cast to prepare a current collector grid having a length of 130.0 mm, a width of 115.0 mm, and a thickness of 4.05 mm. After filling the positive electrode active material paste into the current collector grid, a positive electrode plate was prepared under the following aging and drying conditions.

Aging condition 1 ... temperature: 80 ° C, humidity: 98%, time: 10 hours Aging condition 2: temperature: 65 ° C, humidity: 75%, time: 11 hours Drying conditions ··· temperature: 60 ° C , Time: 24 hours <Battery assembly>
Three unformed negative plates and two unformed negative plates are placed through glass fiber retainers (separators for control valve type lead-acid batteries) so that unformed negative plates and unformed positive plates are laminated alternately. After laminating the conversion positive electrode plate, the ears of the same polarity electrode plate were connected with a strap to prepare an electrode plate group. Insert the electrode plate group into the battery case and inject a dilute sulfuric acid electrolyte with a specific gravity of 1.050 (20 ° C). The applied amount is 250% of the theoretical capacity, the formation time is 40 hours, and the ambient temperature is 40 ° C. Chemicalized with conditions. After the chemical conversion, the electrolytic solution is discharged, and after laminating one pre-formed negative electrode plate and two pre-formed positive plates through a glass fiber retainer, a predetermined amount of electrolytic solution (specific gravity 1.275 dilute sulfuric acid) is injected. A control valve type lead-acid battery was assembled with a safety valve.

(Example 2) to (Example 16) and (Comparative Example 1) to (Comparative Example 7)
A control valve type lead-acid battery was obtained in the same manner as in Example 1 except that the negative electrode plate was made of the material and composition shown in Table 1.

<Evaluation of battery performance>
About said control valve type lead acid battery, battery performance (initial capacity and cycling characteristics) was measured as follows. The measurement results of the initial capacity and cycle characteristics of Comparative Example 1 were set to 100, and the respective characteristics of the examples were relatively evaluated. The results are shown in Table 1.

(Initial capacity)
An initial capacity test was performed on the above-mentioned control valve type lead storage battery by the following procedures (a) to (d) to evaluate the battery performance. This test was performed in an environment controlled at 25 ° C.

The test was conducted according to the following procedure with the 10 hour rate capacity of the battery set to 4 Ah.
(A) Discharge at 0.4 A and final voltage of 1.80 V (b) Charge for 24 hours at 0.4 A and control voltage of 2.42 V (c) Pause for at least 24 hours (d) Above (a) to Repeat step (c) twice.

  The second discharge capacity of the lead storage battery was used as the initial capacity. The initial capacity was evaluated according to the following criteria.

○: Initial capacity improved (when initial capacity exceeds 100 and less than 120)
Δ: Initial capacity was maintained (when initial capacity is 95 or more and 100 or less)
×: Initial capacity decreased (when initial capacity is less than 95)
(Cycle characteristics (PSOC cycle test of lead acid battery))
The above-mentioned control valve type lead-acid battery was evaluated by performing a PSOC cycle test according to the following procedures (e) to (h). This test was performed in an environment controlled at 25 ° C.

The test was conducted according to the following procedure with the 10 hour rate capacity of the battery set to 4 Ah.
(E) Discharge at 0.4 A for 9 hours (f) Charge at 2.0 A for 1 hour (g) Charge at 1.6 A for 1.25 hours (h) Repeat in the above steps (e) to (g) The discharge capacity at a 10-hour rate is measured every 100 cycles.

  The number of cycles when the discharge capacity of the lead storage battery reached 70% of the initial capacity ratio was evaluated as the PSOC life cycle characteristics. The evaluation of cycle characteristics was performed according to the following criteria.

A: Cycle characteristics are significantly improved (when cycle characteristics are 130 or more)
○: Cycle characteristics are maintained or improved (when cycle characteristics are 100 or more and less than 130)
X: The cycle characteristic decreased (when the cycle characteristic is less than 100)
The battery performance of the control valve type lead storage battery was comprehensively evaluated from the initial capacity and cycle characteristics evaluated in this way. The overall evaluation was performed according to the following criteria.

A: The initial capacity is maintained or improved, and the cycle characteristics are remarkably improved (when the initial capacity exceeds 100 and the cycle characteristics are 130 or more).
●: Both initial capacity and cycle characteristics improved (when initial capacity exceeds 100 and cycle characteristics exceed 100 and less than 130)
○: The cycle characteristics were improved while maintaining the initial capacity (when the initial capacity was 95 to 100 and the cycle characteristics exceeded 100 and less than 130).
X: At least one of the initial capacity and the cycle characteristics decreases (when the initial capacity is less than 95 or when the cycle characteristics are 100 or less).

なお、表１中の各材料の詳細は以下の通りである。

The details of each material in Table 1 are as follows.

UP-5: Graphite (manufactured by Nippon Graphite Industries Co., Ltd.) having a DBP oil absorption of 220 ml / 100 g and an average particle diameter (D50) of 5 μm,
UP-10: Graphite (manufactured by Nippon Graphite Co., Ltd.) having a DBP oil absorption of 180 ml / 100 g and an average particle diameter (D50) of 10 μm,
SP-20: Graphite (manufactured by Nippon Graphite Industry Co., Ltd.) having a DBP oil absorption of 90 ml / 100 g and an average particle diameter (D50) of 12 μm,
ACB150: Graphite (manufactured by Nippon Graphite Industries Co., Ltd.) having a DBP oil absorption of 75 ml / 100 g and an average particle diameter (D50) of 50 μm,
ACB100: graphite having a DBP oil absorption of 55 ml / 100 g and an average particle diameter (D50) of 80 μm (manufactured by Nippon Graphite Industries Co., Ltd.)
ACB100 (classification): graphite having a DBP oil absorption of 50 ml / 100 g and an average particle diameter (D50) of 100 μm (the ACB100 is classified by the inventor to increase the average particle diameter of ACB100),
ACB50: graphite having a DBP oil absorption of 40 ml / 100 g and an average particle diameter (D50) of 300 μm (manufactured by Nippon Graphite Industries Co., Ltd.)
Denka Black: Acetylene Black (manufactured by Denki Kagaku Kogyo Co., Ltd.),
Vulcan XC72: Furnace Black (manufactured by CABOT),
Pearl Rex DP: High purity modified sodium lignin sulfonate (manufactured by Nippon Paper Industries Co., Ltd.)
Vanillex N: high-purity partially desulfurized sodium lignin sulfonate (manufactured by Nippon Paper Industries Co., Ltd.).

  From Table 1, on the basis of Comparative Example 1, in Examples 1 to 5 (average particle size: 5 to 80 μm, DBP oil absorption: 55 to 220 ml / 100 g), the cycle capacity is maintained or improved while maintaining the initial capacity. It can be seen that it has improved. Among these, in Examples 1 to 4 (average particle diameter: 5 to 50 μm, DBP oil absorption: 75 to 220 ml / 100 g), it can be seen that not only the cycle characteristics are improved but also the initial capacity is improved. Further, in Examples 1 to 3 (average particle size: 5 to 12 μm, DBP oil absorption: 90 to 220 ml / 100 g), the characteristics are remarkably improved with the improvement of the initial capacity (all the cycle characteristics are 130 or more). I understand that.

  In Comparative Example 2 (when both the average particle diameter and DBP oil absorption amount do not satisfy the conditions of the present invention), the initial capacity was reduced (the initial capacity was less than 95). Further, even in Comparative Example 3 (when the DBP oil absorption amount satisfies the conditions of the present invention but the average particle diameter does not satisfy the conditions of the present invention), the initial capacity was reduced (the initial capacity was not less than 95).

  Further, in Examples 6 to 10 (average particle diameter: 10 μm, DBP oil absorption: 180 ml / 100 g, addition amount: 0.5 to 5.0% by mass of graphite), cycle characteristics while maintaining or improving the initial capacity It can be seen that is improved. Among these, in Examples 6 to 9 (average particle size: 10 μm, DBP oil absorption: 180 ml / 100 g, addition amount: 0.5 to 3.0% by mass of graphite), not only the cycle characteristics were improved but also the initial capacity. It can also be seen that Further, in Examples 7 to 9 (average particle size: 10 μm, DBP oil absorption: 180 ml / 100 g, addition amount: 1.0 to 3.0% by mass of graphite), the cycle capacity is remarkably improved as the initial capacity is improved. It can be seen that the cycle characteristics are 130 or more. In Comparative Example 4 (when no graphite was added), there was almost no change in the cycle characteristics, and in Comparative Example 5 (when the amount of graphite added was 7% by mass), both the initial capacity and the cycle characteristics were lowered.

  Furthermore, in Examples 11 to 15 (addition amount of acetylene black: 0.1 to 5.0% by mass), the addition amount of graphite (average particle size: 10 μm, DBP oil absorption: 180 ml / 100 g) is 1% by mass. It can be seen that even when the amount is relatively small, the initial capacity is maintained or improved and the cycle characteristics are improved. Among these, in Examples 11-14 (addition amount of acetylene black is 0.1 to 3.0 mass%), it can be seen that not only the cycle characteristics are improved but also the initial capacity is improved. Furthermore, in Examples 13 and 14 (addition amount of acetylene black is 1.5 to 3.0% by mass), the initial capacity is improved and the cycle characteristics are remarkably improved (both the cycle characteristics are 130 or more). I understand that. In Comparative Example 6 (when acetylene black was not added), the cycle characteristics were lowered, and in Comparative Example 7 (when the amount of acetylene black added was 7% by mass), both the initial capacity and the cycle characteristics were lowered.

  It was also found that Example 16 (when furnace black was used instead of acetylene black) improved the cycle characteristics while maintaining the initial capacity. However, when Example 2 is compared with Example 16, it can be seen that when acetylene black is used for furnace black, not only the cycle characteristics are improved but also the initial capacity is improved.

  Thus, by providing the negative electrode plate that satisfies the conditions of the present invention, it is possible to obtain a control valve type lead storage battery having excellent cycle characteristics while maintaining or improving the initial capacity.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to these embodiment and an Example. That is, the conditions described in the above embodiments and examples can be changed based on the technical idea of the present invention unless otherwise specified.

According to the present invention, in the valve-regulated lead-acid battery operated in a partially charged state, in addition to carbon black, the negative electrode plate contains graphite having an average particle size of 90 μm or less and a DBP oil absorption of 55 ml / 100 g or more. The graphite content is 0.5 to 5.0 mass% with respect to 100 mass% of the negative electrode active material, and the carbon black content is 0.1 to 5.0 mass with respect to 100 mass% of the negative electrode active material. By setting it as the mass%, the control valve type lead acid battery which is excellent in cycling characteristics can be provided.

Claims (8)

Comprising a negative electrode plate includes a negative electrode active material and carbon black, a valve-regulated lead-acid battery,
The negative electrode plate further includes graphite having an average particle diameter of 1 μm to 90 μm and a DBP oil absorption of 55 ml / 100 g or more,
The graphite content is 0.5 to 5.0% by mass with respect to 100% by mass of the negative electrode active material,
Content of the said carbon black is 0.1-5.0 mass% with respect to 100 mass% of said negative electrode active materials, The control valve type lead acid battery characterized by the above-mentioned.   2. The control valve type lead storage battery according to claim 1, wherein the graphite has an average particle diameter of 1 μm to 60 μm and a DBP oil absorption of 65 ml / 100 g or more.   2. The control valve type lead storage battery according to claim 1, wherein the graphite has an average particle diameter of 1 μm to 20 μm and a DBP oil absorption of 85 ml / 100 g or more.   The valve-regulated lead-acid battery according to claim 1, wherein a content of the graphite is 0.5 to 3.0 mass% with respect to 100 mass% of the negative electrode active material.   The valve-regulated lead-acid battery according to claim 1, wherein a content of the graphite is 1.0 to 3.0 mass% with respect to 100 mass% of the negative electrode active material.   The valve-regulated lead-acid battery according to any one of claims 1 to 5, wherein a content of the carbon black is 0.1 to 3.0 mass% with respect to 100 mass% of the negative electrode active material.   The valve-regulated lead-acid battery according to any one of claims 1 to 5, wherein a content of the carbon black is 1.5 to 3.0 mass% with respect to 100 mass% of the negative electrode active material. The control valve type lead acid battery according to any one of claims 1 to 5, wherein the carbon black is acetylene black.