NOVELTY - Silica-coated metal particle (S1) (101) comprises metal core (110) having diameter of 0.5-5000000 nm; and coating (120) with thickness of 0.2-200 nm over the metal core, where the coating comprises silica; and at least one pore (130) that passes through coating to the metal core, where the pore is configured so as to allow oxidizing agent (140) to contact metal core.    USE - In power transmission device such as microprocessor, server, electronic storage medium, air conditioner, refrigerator, power supply, radiator, furnace, reaction chamber, generator, heater in building or vehicle, radiator, defroster, engine block, surface heater, hydraulic system, stove, hot plate or auxiliary power supply used for generating, transmitting and/or storing power or energy in the form of heat, light and electricity performed within or near an item that requires both heating and cooling such as vehicle (e.g. electric vehicle, hybrid-electric vehicle, or fuel cell vehicle), portable building, computer server, or electronically-readable medium.    ADVANTAGE - The coated particles allow for repeated cycles of oxidation and/or reduction without increasing the size and/or altering the surface chemistry of particle. The coating can provide substrate for transmitting heat through e.g. reduction and/or oxidation processes that can be used efficiently for repeated uses. Since the core particles are coated with conductive silica layers, voltage can be easily applied to core particles. That is, the oxidized metal core (after the exothermic process) can be reduced (heat accumulation) using power source. Thus, metal core separation and conductivity are both achieved. The system for transmission of heat and/or energy in electrical device, such as electrical car, using silica-coated metal particle, is renewable, lightweight and high-efficiency power generating system.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) collection of silica-coated metal particles comprising at least 10000 of silica-coated metal particle (S1), where at least 90% of population has surface of metal core that is in oxidized or reduced state;    (2) method (M1) of transmitting power involving providing silica-coated metal particle (S1); reducing the metal core to accumulate heat; and oxidizing metal core, to generate heat;    (3) method (M2) of manufacturing silica-coated metal particle (S1) involving providing metal core; coating the metal core in silica to form silica-coated core; drying the silica-coated core; and baking the particle in stream of gas to form silica-coated metal particle (S1) comprising pore that passes through coating to metal core; and    (4) power transmission device comprising silica-coated metal particle (S1); first chamber configured to allow reduction of the particle; second chamber configured to allow oxidation of particle; passage connecting the first chamber to second chamber, and configured to allow particle to flow from first chamber to second chamber; and apparatus configured to receive heat produced by oxidation of particle in second chamber.    DESCRIPTION OF DRAWING(S) - The figure shows drawing of silica-coated metal particle.    Silica-coated metal particle (101)    Metal core (110)    Coating (120)    Pore (130)    Oxidizing agent (140)