A system and a method for an energy harvesting and storage apparatus including a flexible substrate, an energy harvesting device disposed on the flexible substrate, the energy harvesting device is configured to convert mechanical energy into electrical energy, an energy storage device disposed on the flexible substrate and in electrical communication with the energy harvesting device and configured to receive and store the electrical energy from the energy harvesting device.

A system and a method for an energy harvesting and storage apparatus including a flexible substrate, an energy harvesting device disposed on the flexible substrate, the energy harvesting device is configured to convert mechanical energy into electrical energy, an energy storage device disposed on the flexible substrate and in electrical communication with the energy harvesting device and configured to receive and store the electrical energy from the energy harvesting device.

Provided is a negative electrode for use in a zinc secondary battery, including a negative electrode active material containing ZnO particles and Zn particles, and a nonionic water-absorbing polymer in an amount of 0.01 to 6.0 parts by weight on a solid basis, based on the content of the ZnO particles being 100 parts by weight.

Provided is a negative electrode for use in a zinc secondary battery, including a negative electrode active material containing ZnO particles and Zn particles, and a nonionic water-absorbing polymer, and at least a portion of the ZnO particles is covered with the nonionic water-absorbing polymer.

A secondary battery negative electrode according to the invention includes: a three-dimensional current collector formed of a self-supporting sponge-like structure of carbon nanotubes; a metal active material contained inside the three-dimensional current collector; and a plurality of seed particles contained inside the three-dimensional current collector and made of a material different from the metal active material, in which the secondary battery negative electrode does not include a foil of the metal active material.

Provided is an air electrode/LDH separator assembly including: a rigid porous layer having rigidity and air permeability, wherein the rigidity is defined as a proportion of displacement in a compression direction of less than 3% when pressurized at 0.1 MPa; an air electrode layer that covers both sides of the rigid porous layer, or both sides and end faces of the rigid porous layer provided that at least one end face is excluded; and a layered double hydroxide (LDH) separator that covers an outside of the air electrode layer; wherein i) the rigid porous layer is made of a metal or an electrically conductive ceramic, whereby the rigid porous layer itself functions as a positive electrode current collector, or ii) the rigid porous layer is made of an insulating material and is covered with a porous metal layer, whereby the porous metal layer functions as a positive electrode current collector.

A solid, ionically conductive, non-electrically conducting polymer material with a plurality of monomers and a plurality of charge transfer complexes, wherein each charge transfer complex is positioned on a monomer.

A solid, ionically conductive, non-electrically conducting polymer material with a plurality of monomers and a plurality of charge transfer complexes, wherein each charge transfer complex is positioned on a monomer.

A secondary battery having high electromotive force and including less lead or being free of lead is provided. The secondary battery includes a positive electrode including a positive electrode active material containing manganese oxide, a negative electrode including a negative electrode active material containing at least one selected from zinc, gallium, and tin, and an electrolytic solution containing at least one selected from phosphoric acid and organic oxoacid and having a pH of less than 7 at 25° C. This secondary battery has an open circuit voltage of more than 1.6 V in a fully charged state.

A secondary battery having high electromotive force and including less lead or being free of lead is provided. The secondary battery includes a positive electrode including a positive electrode active material containing manganese oxide, a negative electrode including a negative electrode active material containing at least one selected from zinc, gallium, and tin, and an electrolytic solution containing at least one selected from phosphoric acid and organic oxoacid and having a pH of less than 7 at 25° C. This secondary battery has an open circuit voltage of more than 1.6 V in a fully charged state.