摘要:
A power storage device with high capacity or high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode includes an active material, a first binder, and a second binder. The specific surface area of the active material is S [m2/g]. The weight of the active material, the weight of the first binder, and the weight of the second binder are a, b, and c, respectively. The solution of {(b+c)/(a+b+c)}×100÷S is 0.3 or more. The electrode includes a first film in contact with the active material. The first film preferably includes a region in contact with the active material. The first film preferably includes a region with a thickness of 2 nm or more and 20 nm or less. The first film contains a water-soluble polymer.
摘要:
To provide a manufacturing method of graphene oxide that allows mass production through a relatively simple process, at low costs, and with safety and efficiency. A hydrogen peroxide solution, sulfuric acid, and flake graphite are put in a reaction container, and the mixture is stirred to obtain expansion graphite. The synthesized expansion graphite is washed not with pure water but with a saturated aqueous solution of magnesium sulfate (MgSO4) or an organic solvent, whereby a large amount of sulfuric acid is contained between graphite layers. The expansion graphite is subjected to heat treatment or microwave irradiation to form expanded graphite, and a graphite layer is peeled by ultrasonic treatment and then oxidized to form a graphene compound.
摘要:
An electrode for a power storage device with good cycle characteristics and high charge/discharge capacity is provided. In addition, a power storage device including the electrode is provided. The electrode for the power storage device includes a conductive layer and an active material layer provided over the conductive layer, the active material layer includes graphene and an active material including a plurality of whiskers, and the graphene is provided to be attached to a surface portion of the active material including a plurality of whiskers and to have holes in part of the active material layer. Further, in the electrode for the power storage device, the graphene is provided to be attached to a surface portion of the active material including a plurality of whiskers and to cover the active material including a plurality of whiskers. Further, the power storage device including the electrode is manufactured.
摘要:
A lithium secondary battery which has high charge-discharge capacity, can be charged and discharged at high speed, and has little deterioration in battery characteristics due to charge and discharge is provided. A negative electrode includes a current collector and a negative electrode active material layer. The current collector includes a plurality of protrusion portions extending in a substantially perpendicular direction and a base portion connected to the plurality of protrusion portions. The protrusion portions and the base portion are formed using the same material containing titanium. A top surface of the base portion and at least a side surface of the protrusion portion are covered with the negative electrode active material layer. The negative electrode active material layer may be covered with graphene.
摘要:
When a hole in a separator is clogged, the cycle characteristics of a battery might be lowered and the internal resistance of a battery might be increased to reduce the output. Thus, a means for suppression of or recovery from degradation due to a clogged separator in a battery such as a lithium-ion secondary battery is provided. When reverse pulse current is supplied multiple times during charge, a separator is prevented from being clogged and a voltage increase (increase in internal resistance) during charge is suppressed, so that charge can be normally performed repeatedly.
摘要:
A power storage device is reduced in weight. A metal sheet serving as a negative electrode current collector is separated and another negative electrode current collector is formed. For example, through the step of forming silicon serving as a negative electrode active material layer over a titanium sheet and then performing heating, the titanium sheet can be separated. Then, another negative electrode current collector with a thickness of more than or equal to 10 nm and less than or equal to 1 μm is formed. Thus, light weight of the power storage device can be achieved.
摘要:
Provided are an electrode for a power storage device having much better charge/discharge characteristics and a power storage device using the electrode. A plurality of cavities is provided in a surface of an active material layer over a current collector. A graphene covering the active material layer facilitates rapid charge/discharge and prevents breakdown of the current collector caused by charge/discharge. With improved charge/discharge characteristics, an electrode for a power storage device which does not easily deteriorate and a power storage device using the electrode can be provided.
摘要:
A power storage device is reduced in weight. A metal sheet serving as a negative electrode current collector is separated and another negative electrode current collector is formed. For example, through the step of forming silicon serving as a negative electrode active material layer over a titanium sheet and then performing heating, the titanium sheet can be separated. Then, another negative electrode current collector with a thickness of more than or equal to 10 nm and less than or equal to 1 μm is formed. Thus, light weight of the power storage device can be achieved.
摘要:
A lithium secondary battery which has high charge-discharge capacity, can be charged and discharged at high speed, and has little deterioration in battery characteristics due to charge and discharge is provided. A negative electrode includes a current collector and a negative electrode active material layer. The current collector includes a plurality of protrusion portions extending in a substantially perpendicular direction and a base portion connected to the plurality of protrusion portions. The protrusion portions and the base portion are formed using the same material containing titanium. A top surface of the base portion and at least a side surface of the protrusion portion are covered with the negative electrode active material layer. The negative electrode active material layer may be covered with graphene.
摘要:
To provide a power storage device whose charge and discharge characteristics are unlikely to be degraded by heat treatment. To provide a power storage device that is highly safe against heat treatment. The power storage device includes a positive electrode, a negative electrode, a separator, an electrolytic solution, and an exterior body. The separator is located between the positive electrode and the negative electrode. The separator contains polyphenylene sulfide or solvent-spun regenerated cellulosic fiber. The electrolytic solution contains a solute and two or more kinds of solvents. The solute contains LiBETA. One of the solvents is propylene carbonate.