Insight into thermal regulation of supercapacitors via surface-engineered phase change microcapsules

Constructing efficient thermal management system to settle the thermal runaway of energy storage devices via employing phase change microcapsules (MEPCMs) is of great significance. However, it is still a challenge that the conventional MEPCMs go against the electrochemical performance and hardly be homogenously fixed in the electrodes. In order to conquer these long-standing critical issues, we designed a novel electrochemically active double-shell phase change microcapsule by introducing polypyrrole on the surface of dense amine resin shell of the conventional inert MEPCM. The active MEPCMs@PPy are uniformly immobilized on the surface of the electrode material using reduced graphene oxide to ensure the stable and efficient operation of the flexible supercapacitor. The assembled all-solid-state supercapacitor containing MEPCMs@PPy (SCs@MEPCMs@PPy) lagged 103 s to 55 degrees C than the SCs@00 without the added phase change material. At a high temperature of 55 degrees C and a scan rate of 50 mVs (1), SCs@MEPCMs@PPy exhibits an areal specific capacitance of 110.6 mA cm (2), which is higher than that of the original SCs@MEPCMs. A capacitance retention of 79.8 % and coulombic efficiency of 98.4 % can be reached after 3000 cycles. This study opens a new avenue for developing applicable microencapsulated phase change materials in temperature-regulated electrode systems for supercapacitors and alkaline-ion batteries. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Constructing an efficient thermal management system using phase change microcapsules (MEPCMs) is important for resolving the thermal runaway issue in energy storage devices. Conventional MEPCMs, however, hinder the electrochemical performance and are difficult to uniformly fix in the electrodes. To address these challenges, a novel electrochemically active double-shell phase change microcapsule was designed by incorporating polypyrrole onto the dense amine resin shell of the inert MEPCM. The active MEPCMs@PPy were uniformly immobilized on the electrode material's surface using reduced graphene oxide, resulting in a stable and efficient operation of the flexible supercapacitor.