Thermoelectric generator (TEG) has been proved as a promising technology for directly converting heat into electricity based on Seebeck effect. On the contrary, this electricity can trigger a solid-state cooling based on conventional Peltier effect. However, these two effects induce a coupling between heat and electric flux, especially for the quantitative relationship still remaining a mystery. Here, we show experimental evidence and theoretical calculation for the coupling by monitoring transient response of fluid temperature and output power. The experimental maximum heat flow in open circuit is 1162 W at cold fluid flow rate ${\dot{V}}_{\mathrm{c}}$ = 0.3 m³/h and fluid temperature difference ΔT_f = 70 °C, enhanced by 13% owing to heat compensation from intrinsic coupling in closed-loop circuit. Meanwhile, the measured maximum output power of TEG is 18.2 W, and subsequently decreases to 15.4 W due to the objective existence of coupling. This double-edged sword in coupling vigorously inspires the potential applications in heat-dissipation situation such as spacecraft, electronic components, photovoltaic, refrigerator and etc. Present findings open a novel avenue for manipulating heat-electricity conversion in practical engineering.

热电发电机（TEG）已被证明是一种基于塞贝克效应将热量直接转化为电能的有前途的技术。相反，这种电可以触发基于传统珀耳帖效应的固态冷却。然而，这两种效应导致了热通量和电通量之间的耦合，尤其是数量关系仍然是个谜。在这里，我们通过监测流体温度和输出功率的瞬态响应来展示耦合的实验证据和理论计算。在冷流体流速下，开路中的实验最大热流为 1162 W${\dot{伏}}_{\mathrm{C}}$ = 0.3 m ³ /h 和流体温差 Δ T _f  = 70 °C，由于闭环回路中固有耦合的热补偿，提高了 13%。同时，实测TEG的最大输出功率为18.2 W，随后由于耦合的客观存在而降低到15.4 W。这种耦合中的双刃剑极大地激发了在航天器、电子元件、光伏、冰箱等散热领域的潜在应用。目前的研究结果为在实际工程中操纵热电转换开辟了一条新途径。