Heat rectification effect enables all-season thermal management-electricity cogeneration using dual-mode metawood bricks with aligned semi-pores design

Energy conversion systems can be advanced by harvesting and transforming thermal energy, such as cooling or heating, into electrical power. Still, the traditionally designed thermoelectric devices still suffer from low output voltage, poor mechanical properties and cannot work in all seasons due to a lack of an effective thermal regulation approach. Herein, based on the heat rectification effect, we report dual-mode metawood bricks (DM) with a unique internal aligned semi-pores design and double-sided architecture achieved by a partial level (60 %) of densification scheme and surface coating modifications. In cooling mode, the upper side of the wood, which had a high solar reflectivity and infrared emissivity, promoted heat transfer from inner space to outer space with interface energy capture of the MXene layer. In heating mode, high solar absorption and low infrared emissivity of the MXene layer prevents heat loss. The resulting bricks enable all-weather thermal management by a large temperature gradient, with sub-ambient cooling of 4.7 °C during hot weather and above-ambient heating of 17.0 °C during cold weather. Outdoor practice confirms that the integrated single thermoelectric device generates a power density of 10.4 mW/cm 2 in heating mode and 3.9 mW/cm 2 in cooling mode, which is higher than previous reports. Moreover, these bricks demonstrate an impressive high mechanical strength of 36.0 MPa and water resistance capabilities, which are attractive features for sustainable, design-customizable, and practical thermo-electronic devices.