This work presents the computational modeling of a fast-charging battery-like thermal energy storage system using a heat exchanger with adsorbent-coated microchannels and a condenser. The utilization of microchannels leads to an extreme asymmetry in the operation of the energy storage system, where the charging time becomes <10 % of the total cycle time. When the system is charged with a 90 °C heat source, it can recover heat at the same temperature for ten times longer. Using silica gel as the adsorbent and water as the medium, this system can store up to 70 kWh m−3 of heat, which is >3.5 times energy over the conventional thermal energy storage options, including latent and sensible heat techniques. Additional advantages of this system include a perfectly scalable operation, flexibility to use diverse adsorbents and refrigerants and location independence, warranting a detailed experimental validation.