A negative electrode used in a nickel metal hydride secondary battery includes a negative electrode core body and a negative electrode mixture carried on the negative electrode core body. The negative electrode mixture includes hydrogen storage alloy powder which is an aggregate of hydrogen storage alloy particles, a binder, and a thickener. The hydrogen storage alloy particles have a volume mean particle size of 40 μm or less and a concentration of chlorine of not less than 180 ppm to not more than 780 ppm.

A negative electrode used in a nickel metal hydride secondary battery includes a negative electrode core body and a negative electrode mixture carried on the negative electrode core body. The negative electrode mixture includes hydrogen storage alloy powder which is an aggregate of hydrogen storage alloy particles, a binder, and a thickener. The hydrogen storage alloy particles have a volume mean particle size of 40 μm or less and a concentration of chlorine of not less than 180 ppm to not more than 780 ppm.

A main object of the present disclosure is to provide a cathode active material capable of suppressing the reaction with a solid electrolyte. The present disclosure achieves the object by providing a coated cathode active material comprising: a cathode active material, and a coating portion coating at least a part of a surface of the cathode active material, and the coating portion includes a scandium lithium phosphate based compound or a lithium borate based compound.

Energy storage devices, battery cells, and batteries of the present technology may include a first current collector and a second current collector. The batteries may include an anode material coupled with the first current collector. The batteries may include a cathode material coupled with the second current collector. The batteries may also include a separator positioned between the cathode material and the anode material. The batteries may include a hydrogen-scavenger material incorporated within the anode active material or the cathode active material. The hydrogen scavenger material may absorb or react with hydrogen at a temperature above or about 20° C.

A method of synthesizing an electrode material for lithium ion batteries from Fe.sub.3O.sub.4 nanoparticles and multiwalled carbon nanotubes (MWNTs) to yield (Fe.sub.3O.sub.4-NWNTs) composite heterostructures. The method includes linking the Fe.sub.3O.sub.4 nanoparticles and multiwalled carbon nanotubes using a π-π interaction synthesis process to yield the composite heterostructure electrode material. Since Fe.sub.3O.sub.4 has an intermediate voltage, it can be considered an anode (when paired with a higher voltage material) or a cathode (when paired with a lower voltage material).

A nickel-containing hydroxide particle covered with cobalt capable of preventing cracks and fissures in the particle and fine powder from being generated due to having an excellent particle strength is provided. The nickel-containing hydroxide particle covered with cobalt, including a covering layer containing cobalt oxyhydroxide formed on a nickel-containing hydroxide particle, wherein an average particle strength is 65.0 MPa or more and 100.0 MPa or less for a particle diameter with a cumulative volume percentage of 50% by volume (D50) of 10.0 μm or larger and 11.5 μm or smaller.

A nickel-containing hydroxide particle covered with cobalt capable of preventing cracks and fissures in the particle and fine powder from being generated due to having an excellent particle strength is provided. The nickel-containing hydroxide particle covered with cobalt, including a covering layer containing cobalt oxyhydroxide formed on a nickel-containing hydroxide particle, wherein an average particle strength is 65.0 MPa or more and 100.0 MPa or less for a particle diameter with a cumulative volume percentage of 50% by volume (D50) of 10.0 μm or larger and 11.5 μm or smaller.

There is provided a secondary zinc battery including: a unit cell including; a positive-electrode plate including a positive-electrode active material layer and a positive-electrode collector; a negative-electrode plate including a negative-electrode active material layer containing zinc and a negative-electrode collector; a layered double hydroxide (LDH) separator covering or wrapping around the entire negative-electrode active material layer; and an electrolytic solution. The positive-electrode collector has a positive-electrode collector tab extending from one edge of the positive-electrode active material layer, and the negative-electrode collector has a negative-electrode collector tab extending from the opposite edge of the negative-electrode active material layer and beyond a vertical edge of the LDH separator. The unit cell can thereby collects electricity from the positive-electrode collector tab and the negative-electrode collector tab. The LDH separator has at least two continuous closed edges, provided that an edge, adjacent to the negative-electrode collector tab, of the LDH separator is open.

There is provided a secondary zinc battery including: a unit cell including; a positive-electrode plate including a positive-electrode active material layer and a positive-electrode collector; a negative-electrode plate including a negative-electrode active material layer containing zinc and a negative-electrode collector; a layered double hydroxide (LDH) separator covering or wrapping around the entire negative-electrode active material layer; and an electrolytic solution. The positive-electrode collector has a positive-electrode collector tab extending from one edge of the positive-electrode active material layer, and the negative-electrode collector has a negative-electrode collector tab extending from the opposite edge of the negative-electrode active material layer and beyond a vertical edge of the LDH separator. The unit cell can thereby collects electricity from the positive-electrode collector tab and the negative-electrode collector tab. The LDH separator has at least two continuous closed edges, provided that an edge, adjacent to the negative-electrode collector tab, of the LDH separator is open.

The invention discloses an active material ball composite layer. The active material ball composite layer includes a plurality of active material balls and an outer binder. The active material ball include a plurality of active material particles and a first conductive material. An inner binder is used to adhere the active material particles and the first conductive material to form the active material balls. Then, the outer binder is used to adhere the active material balls to form the composite layer. The elasticity of the inner binder is smaller than the elasticity of the outer binder. Therefore, the scale of expansion of the active material particles is efficiently controlled during charging and discharging. The unrecoverable voids would be reduced or avoided.