Multienergy-Triggered Composite Phase-Change Materials Based on Graphite Foams Synthesized from Graphite Extracted from Spent Lithium-Ion Batteries
Mingyong Liu, Xiaoguang Zhang, Xianjie Liu, Xiaowen Wu, Xinjian Ye, Jiaxin Qiao, Zhenhua Sun, Xiao Zhu, Zhaohui Huang
Abstract
Multifunctional composite phase-change materials (CPCMs) with dual photo/electrothermal triggers have great potential for sustainable energy utilization. Photo/electric-triggered CPCMs are usually prepared by compounding graphene or carbon nanotubes with phase-change materials (PCMs). However, the practical applications of such materials are limited by the complexity and cost of common preparation methods for the supporting materials. Herein, a template method is developed to prepare graphite foams (GFs) using easily available graphite powder extracted from spent lithium-ion batteries. Paraffin wax (PW) is subsequently incorporated into the GFs as a PCM to synthesize GF-PW CPCMs with superior photo/electrothermal conversion capacity. The prepared GF-PW CPCMs exhibit high latent enthalpy (173.9 to 209.2 J/g) and excellent shape and thermal stability and cycling ability. The inherent high thermal/electrical conductivity and excellent solar light absorption capacity of the GFs fabricated from graphite powder confer the GF-PW CPCMs with excellent photo/electrothermal conversion performance. In addition, the 1:4 GF-PW CPCMs exhibit the highest thermal conductivity of 1.38 W/(m K), which is up to 4.11 times higher than that of pure PW. This work not only opens up a pathway for the utilization of graphite powder extracted from spent lithium-ion batteries, but also provides a facile low-cost method for preparing CPCMs with potential applications in photo/electrothermal energy storage and conversion.