Provides an aqueous binder composition for a secondary battery electrode, comprising a copolymer and a dispersion medium, wherein the copolymer comprises a structural unit (a), a structural unit (b), and a structural unit (c). The binder composition disclosed herein has improved binding capability. In addition, battery cells comprising electrodes prepared using the binder composition disclosed herein exhibits exceptional electrochemical performance.

The present disclosure provides a lithium-ion battery, the lithium-ion battery comprises a positive electrode plate, a negative electrode plate, a separator and an electrolyte. The positive active material comprises a material having a chemical formula of Li.sub.aNi.sub.xCo.sub.yM.sub.zO.sub.2, the negative active material comprises a graphite-type carbon material, the lithium-ion battery satisfies a relationship 58%≤KY.sub.a/(KY.sub.a+KY.sub.c)×100%≤72%. In the present disclosure, by reasonably matching the relationship between the anti-compression capability of the positive active material and the anti-compression capability of the negative active material, it can make the positive electrode plate and the negative electrode plate both have good surface integrity, and in turn make the lithium-ion battery have excellent dynamics performance and excellent cycle performance at the same time.

The purpose of the present invention is to provide a lithium secondary battery having a high energy density and an excellent cycle characteristic. The present invention relates to a lithium secondary battery equipped with a positive electrode, a negative electrode not having a negative electrode active material, a separator placed therebetween, and a fibrous or porous buffering function layer formed on the surface of the separator facing the negative electrode and having ionic conductivity. The positive electrode contains a positive electrode active material and a lithium-containing compound which causes an oxidation reaction and does not substantially cause a reduction reaction in a charge/discharge potential range of the positive electrode active material. In a particle size distribution by the laser diffraction method, the lithium-containing compound has a particle size D.sub.50 (S), which corresponds to a cumulative degree at 50%, of 1.0 μm or more and 20 μm or less and a particle size D.sub.95 (S), which corresponds to a cumulative degree at 95%, of 1.0 μm or more and 30 μm or less.

The purpose of the present invention is to provide a lithium secondary battery having a high energy density and an excellent cycle characteristic. The present invention relates to a lithium secondary battery equipped with a positive electrode, a negative electrode not having a negative electrode active material, a separator placed therebetween, and a fibrous or porous buffering function layer formed on the surface of the separator facing the negative electrode and having ionic conductivity. The positive electrode contains a positive electrode active material and a lithium-containing compound which causes an oxidation reaction and does not substantially cause a reduction reaction in a charge/discharge potential range of the positive electrode active material. In a particle size distribution by the laser diffraction method, the lithium-containing compound has a particle size D.sub.50 (S), which corresponds to a cumulative degree at 50%, of 1.0 μm or more and 20 μm or less and a particle size D.sub.95 (S), which corresponds to a cumulative degree at 95%, of 1.0 μm or more and 30 μm or less.

Described herein are composite anode compositions comprising silicon for use in an electrochemical cell. The composite anode compositions described herein include silicon as an anode active material having a particle size, crystallite size, and surface area that provide desired electrochemical properties. Further provided herein are electrochemical cells comprising the anode compositions and methods of making the same.

A charging method for a secondary battery including a lithium-supplementing material. The method includes acquiring a first state of health of the secondary battery in response to the secondary battery being at a preset charging node, activating the lithium-supplementing material in response to the first state of health being less than or equal to a first threshold to supplement lithium for the secondary battery, performing a charging process on the secondary battery, determining a second state of health of the secondary battery based on a working parameter of the secondary battery in the charging process, and charging the secondary battery in response to the second state of health being greater than a second threshold.

A charging method for a secondary battery including a lithium-supplementing material. The method includes acquiring a first state of health of the secondary battery in response to the secondary battery being at a preset charging node, activating the lithium-supplementing material in response to the first state of health being less than or equal to a first threshold to supplement lithium for the secondary battery, performing a charging process on the secondary battery, determining a second state of health of the secondary battery based on a working parameter of the secondary battery in the charging process, and charging the secondary battery in response to the second state of health being greater than a second threshold.

This application provides a lithium-nickel-manganese-based composite oxide material, where a K value of the lithium-nickel-manganese-based composite oxide material ranges from 1 to 2, and the K value is calculated based on the following formula: K=D.sub.v50/d.sub.v50, where d.sub.v50 is a volume median crystallite diameter of crystal particles of the lithium-nickel-manganese-based composite oxide material; and D.sub.v50 is a volume median particle diameter of the lithium-nickel-manganese-based composite oxide material.

The present disclosure relates to a stretchable electrode, a method for preparing the same and a stretchable battery including the stretchable electrode. The stretchable electrode of the present disclosure, which is prepared by crosslinking a hydroxyl-functionalized fluorine-based polymer binder physically using a ketone-based solvent or chemically with a crosslinking agent, has superior stretchability, has improved interfacial adhesivity to an active material through Fenton's oxidation, exhibits improved stability under various mechanical deformations of the electrode such as stretching, etc. and can uniformly maintain the electrical conductivity, battery capacity and charge-discharge performance of the electrode.

In addition, the stretchable battery of the present disclosure, which includes the stretchable electrode, a stretchable current collector, a stretchable separator and a stretchable encapsulant, has improved stretchability and superior battery stability under various deformations due to high degree of freedom of structures and materials. In addition, the stretchable battery of the present disclosure can be prepared as a fiber battery by printing an electrode and a current collector sequentially on both sides of a stretchable fabric, which can be worn, e.g., around sleeves due to superior stretchability and high structural degree of freedom and retains high battery performance and mechanical stability even under mechanical deformation. Therefore, it can be applied to a mobile display for a health monitoring system or a smartwatch.

According to one embodiment, provided is a secondary battery including a negative electrode containing a titanium-containing oxide, a positive electrode, a separator between the negative electrode and the positive electrode, a first aqueous electrolyte, a second aqueous electrolyte, and a third aqueous electrolyte. The first aqueous electrolyte is held in the negative electrode and contains 0.001% by mass to 0.5% by mass of zinc ions. The second aqueous electrolyte is held in the separator and contains 1% by mass to 5% by mass of a first compound that includes a hydrophobic portion and a hydrophilic portion. The third aqueous electrolyte is held in the positive electrode.