Alkaline electrochemical cells are provided, wherein methods to decrease or eliminate shorting in batteries by preventing zinc oxide reaction precipitate from creating a conductive bridge between the two electrodes. The alkaline electrochemical cell comprising dissolved zinc oxide or zinc hydroxide in at least the electrolyte solution, and/or solid zinc oxide particles or zinc hydroxide in the anode, a silicon donor in the anode, and/or a bilayer separator optimally comprising a high-density layer and a low-density layer.

A battery comprises an anode, a cathode, and a polymer electrolyte disposed between the anode and the cathode. The polymer electrolyte can include an inert hydrophilic polymer matrix impregnated with an aqueous electrolyte. The hydrophilic polymer matrix can include a polar vinyl monomer, an initiator, and a cross-linker. A gassing inhibitor can be included in the polymer electrolyte to help avoid issues with overcharging of the electrodes.

Alkaline electrochemical cells are provided, wherein dissolved zinc oxide or zinc hydroxide is included at least in the free electrolyte solution, and/or solid zinc oxide or zinc hydroxide is included in the anode, so as to slow formation of a zinc oxide passivation layer on a zinc electrode. Methods for preparing such cells are also provided.

An alkaline electrochemical cell has a central cathode having a corresponding cathode current collector electrically connected with a positive terminal of the electrochemical cell. The cathode current collector has a tubular shape, such as a cylindrical shape or rectangular shape, extending parallel with the length of the central cathode. The cathode current collector is embedded within the central cathode, such as at a medial point of a radius of the central cathode, thereby minimizing the distance between the cathode current collector and any portion of the central cathode, thereby increasing the mechanical strength of the cathode and facilitating charge transfer to the cathode current collector.

A battery includes an air cathode, an anode, an aqueous electrolyte, and a housing, wherein the housing includes one or more air access ports defining a total vent area; the battery exhibits a cell limiting current at 1.15V; a ratio of cell limiting current at 1.15 V to total vent area is greater than about 100 mA/mm.sup.2; and the aqueous electrolyte includes an amphoteric fluorosurfactant.

A zinc-air battery cell assembly comprising: a cathode can that includes: a planar base, and an elongated cathode sidewall that extends to a terminal cathode sidewall end, and an anode can that includes: a planar top end, and an elongated anode sidewall that extends to a terminal anode sidewall end, the anode can disposed nested within the cathode can with the elongated anode sidewall disposed parallel and adjacent to the elongated cathode sidewall. The zinc-air battery assembly further includes a cavity defined by the cathode can and the anode can disposed nested within the cathode can, and a grommet that provides a seal between the cathode can and the anode can while also keeping the anode can and the cathode can separate.

A high voltage zinc (Zn)-anode battery comprising a cathode comprising a cathode electroactive material; an anode comprising a Zn electroactive material; a catholyte in contact with the cathode, wherein the catholyte is not in contact with the anode; an anolyte in contact with the anode, wherein the anolyte is not in contact with the cathode; and a separator disposed between the anolyte and the catholyte. The catholyte has a pH of less than 4, and the anolyte has a pH of greater than 10. The separator has ion-selective properties.

Various embodiments are directed to an electrochemical cell having a non-homogeneous anode. The electrochemical cell includes a container, a cathode forming a hollow cylinder within the container, an anode positioned within the hollow cylinder of the cathode, and a separator between the cathode and the anode. The anode comprises at least two concentric anode portions, defined by different anode characteristics. For example, the two anode portions may contain different surfactant types, which provides the two anode portions with different charge transfer resistance characteristics. By lowering the charge transfer resistance of a portion of an anode located proximate the current collector of the cell (and away from the separator) relative to an anode portion located adjacent the separator, improved cell discharge performance may be obtained.

Aspects disclosed in the detailed description include an ingestible power harvesting device and related applications. An ingestible power harvesting device includes a cathode electrode and an anode electrode that can catalyze a power generating reaction to generate a direct current (DC) power when surrounded by an acidic electrolyte. The cathode electrode and the anode electrode are coupled to an encapsulated electronic device that includes power harvesting circuitry configured to harvest the DC power and output a DC supply voltage for a prolonged period. In examples discussed herein, the prolonged period is at least five days. The DC supply voltage powers an electronic circuit in the encapsulated electronic device to support a defined in vivo operation (e.g., controlled drug delivery, in vivo vital signs monitoring, etc.). As such, the ingestible power harvesting device can operate in vivo for the prolonged period without requiring an embedded conventional battery.

Methods and apparatus to form biocompatible energization elements are described. In some embodiments, the methods and apparatus to form the biocompatible energization elements involve forming cavities comprising active cathode chemistry. The active elements of the cathode and anode are sealed with a laminate stack of biocompatible material. In some embodiments, a field of use for the methods and apparatus may include any biocompatible device or product that requires energization elements.