Converting waste heat into electricity is a promising strategy to address the ever-growing energy crisis. Ferromagnets have potential in heat recovery because of their thermo-induced magnetic transition. However, the conventional thermomagnetic generator based on ferromagnets requires rapid temperature fluctuation, which is difficult to be satisfied in a real-world environment. Here, we report a thermomagnetic-electric energy harvester consisting of a piezoelectric film and a magnetic-phase-transition alloy with low magnetization at low temperature but high magnetization at high temperature. The thermomagnetic-electric conversion in this device is a product effect, that is, the heat is first converted to kinetic energy because of thermo-induced magnetic transition, then to electric energy owing to the piezoelectric effect. The maximum short-circuit current and open-circuit voltage of this thermomagnetic-electric energy harvester approach 1.27 μA and 25 V, respectively. The magnetic-phase-transition alloy-based thermomagnetic-electric energy harvester has the capability to automatically convert the waste heat from a high temperature source into electric energy without rapid temperature fluctuation.

中文翻译：

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热磁电转换辅助热量回收

将废热转化为电能是解决不断增长的能源危机的有希望的战略。铁磁体由于其热感应的磁跃迁而具有热回收的潜力。然而，传统的基于铁磁体的热磁发电机需要快速的温度波动，这在现实环境中难以满足。在这里，我们报道了一种由压电膜和磁相变合金组成的热磁电能量收集器，其在低温下磁化强度低，而在高温下磁化强度高。该装置中的热磁电转换是一种乘积效应，也就是说，由于热感应的磁跃变，热量首先转换为动能，然后由于压电效应而转换为电能。该热磁电能量采集器的最大短路电流和开路电压分别接近1.27μA和25V。基于磁性相变合金的热磁电能量收集器具有将高温源的废热自动转换为电能而不会出现快速温度波动的能力。