Thermal properties optimization of lauric acid as phase change material with modified boron nitride nanosheets-sodium sulfate for thermal energy storage

Abstract

Lauric acid as phase change material is broadly used in thermal energy storage, whereas its poor heat transfer performance and low shape-stability hinder the practical application. In this work, a novel lauric acid/modified boron nitriding nanosheets‑sodium sulfate composite phase change material was fabricated by vacuum impregnation. During the fabrication process, sodium sulfate was introduced to improve the porosity and thermal conductivity of composite phase change material. The results show that the load capacity of lauric acid can reach to 83.5 wt% in lauric acid/modified boron nitride nanosheets‑sodium sulfate composite phase change material under the control of sodium sulfate. Besides, the thermal conductivity of lauric acid/modified boron nitride nanosheets-5 wt% sodium sulfate composite phase change material can reach up to 0.744 W/(m.K), which is 196.4 % higher than that of pure lauric acid, as well as the latent heat was increased by 7.49 % than that of composite phase change material without sodium sulfate. After 200 thermal cycles, lauric acid/modified boron nitride nanosheets‑sodium sulfate composite phase change material still has excellent phase change behavior and thermal stability. These properties show that sodium sulfate as a pore-forming agent has great significance for optimizing the thermal performance of composite phase change material. The excellent performance of lauric acid/modified boron nitride nanosheets‑sodium sulfate composite phase change material has a broad application prospect in the field of thermal energy storage and thermal management, etc.