Boosted Thermal Storage Performance of LiOH·H2O by Carbon Nanotubes Isolated Multilayered Graphene Oxide Frames

Yuxian Wang,Jing Gu,Yan Zhu,Guangqian Luo,Xian Li,Huan Liu,Hong Yao,Hongyun Hu,Apostolos Avgeropoulos

doi:10.1155/2022/3109178

Abstract

Cellulose-originated three-dimensional graphene oxide CNT-modified LiOH·H2O (3D-GO-CNTs-LiOH·H2O) was synthesized by the hydrothermal method. LiOH·H2O nanoparticles (5–50 nm) were homogeneously dispersed inside the 3D-GO-CNTs frames. The composite showed enhanced heat storage density, excellent thermal conductivity, and greatly improved hydration rate due to both the hydrophilic reaction interface of 3D-GO-CNTs frames and reduced size of LiOH·H2O nanoparticles. LiOH·H2O content ratio of 23% (3D-GO-CNTs-LiOH·H2O-1) results in best heat storage performance with activation energy of 23.8 kJ/mol, thermal conductivity of 3.06 W/m·K, and heat storage capacity of 2800 kJ/kg. 3D-GO-CNTs-LiOH·H2O shows 4.2 folders heat storage capacity than that of pristine LiOH·H2O after the same hydration reaction. Other composite materials also show good performance: 3D-GO-CNTs-LiOH·H2O-2 (activation energy: 28.5 kJ/mol, thermal conductivity: 2.33 W/m·K, and heat storage capacity: 2051 kJ/kg.); 3D-GO-CNTs-LiOH·H2O-3 (activation energy: 32.3 kJ/mol, thermal conductivity: 2.01 W/m·K, and heat storage capacity: 1983 kJ/kg.). The addition of cellulose originated 3D-GO-CNTs was proved to be an excellent strategy to boost the heat storage performance of LiOH·H2O.

Highlights

Increased fossil energy exhaustion and global warming could be effectively mitigated by reducing CO2 emissions [1, 2]
In order to get more positive effects on the environment by consuming fossil resources and complicated production, cellulose-based material was reported to be successfully fabricated into carbon nanotube (CNT) [43] and graphene oxide (GO) [44] for electronic devices and oil spill cleaning
Increased LiOH·H2O signal at a sequence of 3D-GO-CNTsLiOH·H2O-1, 3D-GO-CNTs-LiOH·H2O-2, and 3D-GOCNTs-LiOH·H2O-3 was in good accordance with increased amount of LiOH·H2O in 3D-GO-CNTs

Summary

Introduction

Increased fossil energy exhaustion and global warming could be effectively mitigated by reducing CO2 emissions [1, 2]. Lithium hydroxide monohydrate (LiOH·H2O) was recently applied to store low temperature thermal energy owing to its high energy density (1400 kJ/kg) and mild reaction conditions (30°C) [14]. It could store the low temperature thermal energy at the range of 80–100°C [15], which was lower than MgSO4 and the heat storage density was higher than it. In order to get more positive effects on the environment by consuming fossil resources and complicated production, cellulose-based material was reported to be successfully fabricated into carbon nanotube (CNT) [43] and graphene oxide (GO) [44] for electronic devices and oil spill cleaning. A highly desired composite with both good thermal conductivity and heat storage capacity was obtained

Materials

Microstructural Characterization

Heat Storage Performance

Conclusions