Latent heat storage (LHS) is considered to be a promising technique for thermal energy storage, due to its high energy storage density and nearly constant working temperature. However, the phase change materials (PCMs) used in LHS usually suffer from low thermal conductivity. In this work, the expanded graphite (EG) was applied to support n-eicosane (C20) via vacuum impregnation to prepare C20/EG composite PCMs. The DSC analysis indicated that the C20/EG₁₅ has latent heat values of 199.4 J g⁻¹ for melting and 199.2 J g⁻¹ for freezing, exhibiting a large thermal storage capacity. The effect of EG on thermal performance was investigated and results suggested that the thermal conductivity of the composite with 15 wt.% EG (3.56 W m⁻¹ K⁻¹) is 14.4 times than that of pure C20 (0.25 W m⁻¹ K⁻¹), and the heating and cooling curves confirmed the EG has substantially improved the thermal transfer rate of samples. Furthermore, the electro-to-heat conversion measurement was carried out under small voltage (1.9–2.1 V), and the C20/EG₁₅ exhibits high electro-to-heat storage efficiency (65.7%) under the voltage of 2.1 V. In all, the composite C20/EG₁₅ is a potential candidate not only for electro-to-heat conversion but also for other thermal storage applications due to large latent heat capacity and high thermal conductivity.

潜热存储（LHS）由于其高的能量存储密度和几乎恒定的工作温度而被认为是一种有前途的热能存储技术。但是，LHS中使用的相变材料（PCM）通常具有较低的热导率。在这项工作中，通过真空浸渍将膨胀石墨（EG）应用于支撑正二十烷（C20），以制备C20 / EG复合PCM。DSC分析表明，C20 / EG _15的潜热值为199.4 J g ^-1熔化和199.2 J g ^-1冷冻，表现出大的蓄热能力。研究了EG对热性能的影响，结果表明，含15 wt。％EG（3.56 W m ^-1 K^-1）是纯C20（0.25 W m ^-1 K ^-1）的14.4倍，并且加热和冷却曲线证实EG大大提高了样品的热传递率。此外，电热转换测量是在较小的电压（1.9–2.1 V）下进行的，并且C20 / EG ₁₅在2.1 V的电压下显示出较高的电热存储效率（65.7％）。总体而言，复合材料C20 / EG ₁₅不仅具有电热转换的潜力，而且由于其大的潜热容量和较高的导热性，还可以用于其他蓄热应用。