BACKGROUND

The present technology generally relates to an anode for a secondary battery including an anode active material and an anode binder, a secondary battery using the anode for a secondary battery, and a battery pack using the secondary battery, an electric motor vehicle, a power storage system, an electric tool, and an electronic device.

Various electronic devices such as a mobile phone and a personal digital assistant (PDA) are becoming widespread, and there is a growing demand for downsizing, weight reduction and long life of the electronic devices. To meet the demand, a battery as a power supply, in particular, a secondary battery which can downsize, can be lightweight, and obtain high energy density is being developed.

The secondary battery is not limited to the electronic devices described above, and application of the secondary battery for other uses is under consideration. Examples of other uses include a battery pack removably mounted on each electronic device or the like, an electric motor vehicle such as an electric vehicle, a power storage system such as a home power server, or an electric tool such as an electric drill.

The secondary battery includes an electrolytic solution together with a cathode and an anode, and the anode includes an anode active material and an anode binder. Since a configuration of the anode has a great effect on battery characteristics, various studies have been made on the configuration of the anode.

SUMMARY

The present technology generally relates to an anode for a secondary battery including an anode active material and an anode binder, a secondary battery using the anode for a secondary battery, and a battery pack using the secondary battery, an electric motor vehicle, a power storage system, an electric tool, and an electronic device.

The electronic devices described above are becoming more high-performance and multifunctional. As a result, the use frequency of the electronic devices and the like is increasing, and the use environment of the electronic devices and the like is expanding. Therefore, the battery characteristics of the secondary battery still have room for improvement.

Accordingly, it is preferable to provide an anode for a secondary battery, a secondary battery, a battery pack, an electric motor vehicle, a power storage system, an electric tool, and an electronic device capable of obtaining excellent battery characteristics.

According to an embodiment of the present technology, an anode for a secondary battery is provided. The anode includes a plurality of first anode active material particles, a plurality of second anode active material particles, a first anode binder, and a second anode binder. The plurality of first anode active material particles include carbon, and an R value of the plurality of first anode active material particles is from 0.35 to 0.45, and a median diameter of the plurality of first anode active material particles is from 5 μm to 14.5 μm. The plurality of second anode active material particles include carbon, and the R value of the plurality of second anode active material particles is from 0.1 to 0.25, and a median diameter of the plurality of second anode active material particles is from 15 μm to 25 μm. A ratio of a weight of the plurality of first anode active material particles to a total of the weight of the plurality of first anode active material particles and a weight of the plurality of second anode active material particles is from 10% by weight to 50% by weight. The first anode binder includes one or both of styrene-butadiene rubber and a derivative thereof, and the second anode binder includes one or both of polyvinylidene fluoride and a derivative thereof.

A secondary battery according to an embodiment of the present technology includes an electrolytic solution together with a cathode and an anode, and the anode has the same configuration as that of the anode as described herein according to an embodiment of the present technology.

According to an embodiment of the present technology, a battery pack, an electric motor vehicle, a power storage system, an electric tool, and an electronic device each include a secondary battery, and the secondary battery has the same configuration as that of the secondary battery as described herein according to the embodiment of the present technology.

Here, the “R value” is measured by analyzing a plurality of first anode active material particles or a plurality of second anode active material particles using Raman spectroscopy. This R value is ID/IG which is a ratio of intensity ID of a Raman spectrum peak existing in a range of 1350 cm−1to 1370 cm−1to intensity IG of a Raman spectrum peak existing in a range of 1570 cm−1to 1630 cm−1. In other words, the R value is an intensity ratio of D band width to G band width. However, a laser used for the Raman spectroscopy is an argon laser (wavelength=514.5 nm).

According to the anode for a secondary battery or the secondary battery of the embodiment of the present technology, the anode includes the plurality of first anode active material particles, the plurality of second anode active material particles, the first anode binder, and the second anode binder, and the conditions as described herein for materials, physical properties, dimensions, and mixing ratios of each of the plurality of first anode active material particles, the plurality of second anode active material particles, the first anode binder, and the second anode binder are satisfied, such that the excellent battery characteristics can be obtained.

In addition, the battery pack, the electric motor vehicle, the power storage system, the electric tool, or the electronic device according to an embodiment of the present technology can also obtain the same effects.

The effects described herein are not necessarily limited, and other suitable properties relating to the present technology may be realized and as further described.

