In the context of 5G, the high-frequency cyclicity and inhomogeneity of heat flow put forward higher requirements for the thermal control system of electronic devices, and there is a great need for thermal management modules with fixed point and high efficiency to ensure the long-term development of electronic devices. Here, we selected four phase change molecules with significant differences in phase change temperatures to be composited with graphene aerogel (GA) to obtain Ei@GA, Tetra@GA, Octa@GA, and 1,10-Deca@GA. Compared with pure phase change molecules, the thermal conductivity has been increased by more than 20%, and the relative enthalpic efficiency is as high as 98.7% or more. Further, we assembled the four phase change composites by “reduction welding” to obtain the integrated, modular thermal management device M₁-PCMs@GA. Simulation of inhomogeneous heat generation in electronics by building an inhomogeneous heat generation platform. Compared with the homogeneous modules M₂-Ei@GA and M₃-1,10-Deca@GA, the effective temperature control time of the customized module M₁-PCMs@GA is extended by 100.0 and 394.3 s, respectively. Therefore, custom-assembled modular thermal management devices have important application prospects in the field of intelligent temperature control of electronic devices, and the idea of cascade assembly enriches the application functions and development direction of intelligent thermal managers.

Photoisomerization-induced phase change are important for co-harvesting the latent heat and isomerization energy of azobenzene molecules. Chemically optimizing heat output and energy delivery at alternating temperatures are challenging because of the differences in crystallizability and isomerization. This article reports two series of asymmetrically alkyl-grafted azobenzene (Azo-g), with and without a methyl group, that have an optically triggered phase change. Three exothermic modes were designed to utilize crystallization enthalpy (∆H_c) and photothermal (isomerization) energy (∆H_p) at different temperatures determined by the crystallization. Azo-g has high heat output (275–303 J g⁻¹) by synchronously releasing ∆H_c and ∆H_p over a wide temperature range (−79 °C to 25 °C). We fabricated a new distributed energy utilization and delivery system to realize a temperature increase of 6.6 °C at a temperature of −8 °C. The findings offer insight into selective utilization of latent heat and isomerization energy by molecular optimization of crystallization and isomerization processes.