An immobilized chalcogen system or body includes a mixture or combination of chalcogen and carbon. The carbon can be in the form of a carbon skeleton. The chalcogen can include oxygen, sulfur, selenium, or tellurium, or a combination of any two or more of oxygen, sulfur, selenium, and tellurium. The activation energy for chalcogen to escape the immobilized chalcogen system or body is 96 kJ/mole.

Provided is particulate for use in a lithium-selenium battery cathode, the particulate comprising one or a plurality of cathode active material particles (selected from Se, lithium polyselenide, sodium polyselenide, potassium polyselenide, a Se alloy or mixture with Sn, Sb, Bi, S, or Te, or a combination thereof) being embraced or encapsulated by a thin layer of a protecting polymer having a lithium ion conductivity from 10.sup.8 S/cm to 510.sup.2 S/cm and a thickness from 0.5 nm to 10 m, wherein the protecting polymer layer contains a polymer selected from poly(ethylene oxide) (PEO), polypropylene oxide (PPO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVDF), poly bis-methoxy ethoxyethoxide-phosphazene, polyvinyl chloride, poly(vinylidene chloride), polydimethylsiloxane, poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP), polyethylene glycol (PEG), chemical derivatives of PEG, poly(ethylene glycol diacrylate) (PEGDA), polyethylene glycol methyl ether (PEG-me), polyethylene glycol dimethyl ether (PEG-de), sulfonated polymers, interpenetrating polymer networks thereof, and combinations thereof.

An electrode material, its manufacturing method, and its use as a cathode material in batteries are provided. The electrode material comprises a plurality of nanoparticles, each having a diameter of approximately 100-400 nm and comprising a core and a shell encapsulating the core. The shell comprises carbon and nitrogen, respectively having a mass fraction of approximately 70-90% and approximately 5-20% relative to a total mass of the shell. The core comprises sulfur, having a mass fraction of approximately 40-97% relative to a total mass of the core. The core has a mass fraction of approximately 50-90% relative to a total mass of each nanoparticle. The electrode material can be used in a cathode of a LiS battery, which has a good energy storage capacity, a high electrochemical stability, and a low capacity decay.

An electroactive material suitable for electrochemical cell electrode wherein the electroactive material includes a chalcogen oligomer that can reversibly deintercalate/reintercalate an anion of the chalcogen, such as La.sub.2O.sub.2S.sub.2, and the electrochemical electrodes and cells containing the electroactive material.

An electrode structure for a positive electrode of a metal-air battery is provided. The electrode structure for a positive electrode of a metal-air battery is formed of a compound of copper, phosphorus, and sulfur and it can comprise a membrane in which a plurality of fibrillated fibers form a network.