A negative electrode active material including a core containing SiO.sub.x (0≤x<2) and a lithium-containing compound, and a shell disposed on the core and containing SiO.sub.x (0≤x<2) and magnesium silicate.

The invention relates to a process for thermally treating, in particular synthesizing and/or drying and calcinating, a nano- and/or micro-scale or nano- and/or micro-crystalline battery material (BM) and/or battery material precursor (BM) in a thermal reactor (1), comprising the steps of: introducing a starting compound (AV) into the reactor (1), the starting material (AV) being a battery material (BM) and/or battery material precursor (BM) and the starting material (AV) being introduced into the reactor (1) in the form of a solution, slurry, suspension or in a solid state of matter, thermally treating the battery material (BM) and/or battery material precursor (BM) carried in a hot gas flow (HGS) in a treatment zone in the reactor (1) at a temperature of 150° C. to 1000° C., and discharging the battery material (BM) obtained from the reactor (1) in the form of a powder.

A secondary battery and a preparation method thereof, and a battery module, battery pack, and apparatus containing a secondary battery are provided. In some embodiments, the secondary battery includes a positive electrode plate, a negative electrode plate, and an electrolyte, where the positive electrode plate includes a positive electrode current collector and a positive electrode film layer that is disposed on at least one surface of the positive electrode current collector and that includes a positive electrode active material, and the negative electrode plate includes a negative electrode current collector and a negative electrode film layer that is disposed on at least one surface of the negative electrode current collector and that includes a negative electrode active material; and the positive electrode active material includes a first material and a second material.

A nanoparticle cluster reduction method yields a new composition of matter including a large percentage (e.g., 75% or higher percentage) of primary nanoparticles in the new composition of matter. The particle reduction method reduces the size of nanoparticle clusters in material of the new composition of matter, allows particle reduction of specific nanoparticle cluster sizes, and allows particle reduction to primary nanoparticles. This new composition of matter can include a high permittivity and high resistivity dielectric compound. This new composition of matter, according to certain examples, has high permittivity, high resistivity, and low leakage current. In certain examples, the new composition of matter constitutes a dielectric energy storage device that is a battery with very high energy density, high operating voltage per cell, and an extended battery life cycle. An example method can include a controlled gas evolution reaction to reduce the size of nanoparticle clusters.

The positive active material for an energy storage device according to one aspect of the present invention has an olivine-type crystal structure, has a surface at least partially coated with carbon, and satisfies either (A) or (B) below. (A) a pore volume in a range of a pore size of 60 nm or more and 200 nm or less determined by a BJH method from a desorption isotherm using a nitrogen gas adsorption method is 0.05 cm.sup.3/g or more and 0.25 cm.sup.3/g or less, and a pore specific surface area in a range of a pore size of 10 nm or more and 200 nm or less using a nitrogen gas adsorption method is 5 m.sup.2/g or more; (B) a full width at half maximum ratio (200)/(131) of a peak corresponding to a (200) plane to a peak corresponding to a (131) plane by a powder X-ray diffraction method using a CuKα ray in a charged state is 1.10 or less.

A positive electrode active material with high charge and discharge capacity is provided. A positive electrode active material with high charge and discharge voltage is provided. A power storage device that hardly deteriorates is provided. A highly safe power storage device is provided. A novel power storage device is provided. A positive electrode active material containing lithium, a plurality of transition metals, oxygen, and an impurity element. The positive electrode active material includes a first region including a surface portion and a second region provided inward from the first region, and the concentration of a transition metal is higher in the first region than in the second region. An impurity region is included between the first region and the second region.

Disclosed are a positive electrode plate and a lithium-ion secondary battery containing the positive electrode plate. In the present disclosure, a polymer electrolyte prepared from a polymer that is different from a polymer used in the conventional technology, and the solid electrolyte, having not only a binding function but also a lithium-conducting function, may replace a binder and a solid electrolyte in an existing electrode plate, so that transmission performance of lithium ions can be effectively improved, and an internal resistance of a solid-state battery can be reduced. In addition, a porosity of a positive electrode plate containing the solid electrolyte is low. This effectively improves energy density and cycling performance of the solid-state battery. The positive electrode plate containing the solid electrolyte may be applied to a battery system having high energy density, thereby broadening a disclosure range of the positive electrode plate.

The battery pack may include a battery pack case and battery cells accommodated in the battery pack case. In each of the first battery cell, the second battery cells, and the third battery cells, when the sum of a discharge capacity corresponding to the first discharge voltage plateau and a discharge capacity corresponding to the second discharge voltage plateau is 100%, a percentage of the discharge capacity corresponding to the second discharge voltage plateau of the third battery cells may be larger than a percentage of the discharge capacity corresponding to the second discharge voltage plateau of the second battery cells, which may be larger than a percentage of the discharge capacity corresponding to the second discharge voltage plateau of the first battery cell.

A battery pack may include a battery pack case and battery cells accommodated in the battery pack case, where an inner space of the battery pack case may include a first area and a second area, a first battery cell may be provided in the first area, second battery cells may be provided in the second area, and the second battery cells may be arranged around the first battery cell; the first battery cell and the second battery cells each may have a first discharge voltage plateau and a second discharge voltage plateau, and an average discharge voltage in the first discharge voltage plateau may be higher than an average discharge voltage in the second discharge voltage plateau.

A battery pack may include a battery pack case and battery cells accommodated in the battery pack case; the inner space of the battery pack case may include a first area, a second area, a third area, and a fourth area; a first battery cell may be provided in the first area, a second battery cell may be provided in the second area, a third battery cell may be provided in the third area, and a fourth battery cell may be provided in the fourth area; and the first battery cell, the second battery cell, the third battery cell, and the fourth battery cell each have a first discharge voltage plateau and a second discharge voltage plateau, and an average discharge voltage in the first discharge voltage plateau may be higher than an average discharge voltage in the second discharge voltage plateau.