Poly(ionic liquid)‐Based Thermal Interface Materials with Enhanced Interfacial Adhesion and Thermal Stability for Advanced Electronic Cooling

Abstract The surge in AI technologies and the new energy sector has intensified the demand for efficient thermal management, now a key technological bottleneck. Silicone‐based thermal interface materials (TIMs) dominate but suffer from oil bleeding, weak interfacial adhesion, and thermal aging. Alternative polymer systems are needed to enable advanced cooling solutions. In this study, poly(1‐butyl‐3‐vinylimidazolium) bis(trifluoromethylsulfonyl)imide (P[Im ₄ ,V]NTf ₂ ), is evaluated for its potential in TIM applications. P[Im ₄ ,V]NTf ₂ exhibits remarkable mechanical and thermal properties, including an elongation exceeding 2400%, robust interfacial adhesion to copper (7.7 MPa) and silicon (8.3 MPa), and high thermal stability with negligible mass loss below 150 °C. It also features rapid self‐healing and recyclability, alongside excellent compatibility with fillers. Aluminum (Al)‐containing composites are prepared via straightforward solution blending of Al powders with P[Im ₄ ,V]NTf ₂ , yielding uniform Al dispersion and achieving thermal conductivity exceeding 3 W m ⁻¹ K ⁻¹ . The intrinsic adhesion of P[Im ₄ ,V]NTf ₂ enables desired interfacial adhesion (≈0.6 MPa) to copper, steel, and glass, far exceeding that of silicone‐based TIMs (≈0.05 MPa). The composite also shows stable thermal performance in device‐level tests, confirming the applicability of structurally diverse poly (ionic liquid)s with commercial fillers for TIM applications.