Renewable energy usage would benefit from efficient and high-capacity long-term heat storage material. However, these types of material solutions still lack reliable and durable operation on bulk level. Previously, we showed that cold-crystallizing material (CCM), which consists of erythritol in cross-linked polymer matrix, stored heat for a long-term period in a milligram scale by supercooling stably and preventing undesired crystallization during storage. Crystallization of CCM can be triggered efficiently by re-heating the material (i.e. cold-crystallization). Supercooling and cold-crystallization are stochastic phenomena which manifest in a way that the properties in bulk scale often deviate from the microscale. In this work, we scale up CCM to a bulk size of 160 g, and analyze its supercooling and crystallization characteristics for long-term heat storage. In order to identify the impact of the scale-up on the tested compositions and to discover optimal storage conditions, CCM samples are maintained in storage mode at constant temperature between 0 and 10 °C and up to 97 days. To this end, the thermal chamber measurement procedure estimates the heat release of CCM samples based on the measured temperature data and the one-dimensional transient heat conduction model. Results indicate that the heat release in cold-crystallization is over 70% of the melting heat. This heat can be stored without reduction for at least 97 days, demonstrating the reliable performance of long-term heat storage. Analysing the thermal properties of CCM compositions indicates a maximum volumetric storage capacity of 250 MJ/m³ and excellent properties for further heat storage applications.

可再生能源的使用将受益于高效和高容量的长期储热材料。但是，这些类型的材料解决方案仍然在批量水平上缺乏可靠且持久的操作。以前，我们显示了由交联聚合物基质中的赤藓糖醇组成的冷结晶材料（CCM）通过稳定地过冷稳定地长期储存了毫克级的热量，并防止了储存过程中不希望的结晶。通过重新加热材料（即冷结晶）可以有效触发CCM结晶。过冷和冷结晶是随机现象，其表现为总体规模的性质经常偏离微观规模。在这项工作中，我们将CCM放大到160 g的体积，并分析其过冷和结晶特性，以长期储存热量。为了确定放大对测试组合物的影响并发现最佳的存储条件，将CCM样品在0至10°C的恒定温度下保存97天，并保持在存储模式下。为此，热室测量程序根据测得的温度数据和一维瞬态热传导模型估算CCM样品的散热量。结果表明，在冷结晶中释放的热量超过熔化热量的70％。可以将这种热量存储至少97天而无需减少，这证明了长期存储的可靠性能。分析CCM组合物的热性能表明最大体积存储容量为250 MJ / m³，优异的性能，可用于进一步的储热应用。