Bottom-up co-assembly of carbon nanotube and soft polymer hybrids: unlocking interstitial channels for enhanced interfacial ion kinetics

While ultra-dense inter-bundle packing in macroscopic carbon nanotube (CNT) assemblies is the conventional paradigm for maximizing mechanical and electrical properties, it inevitably renders the deep internal surface area electrochemically inaccessible. To resolve this fundamental packing-accessibility trade-off, we report a molecular-level spacing strategy utilizing a thermodynamically driven liquid crystalline co-assembly approach. Soft poly(vinyl alcohol) (PVA) chains are intercalated into rigid CNT bundles via strong non-covalent adsorption. The entropic relaxation of these soft chains effectively constructs molecularly secured interstitial channels while preserving the high axial alignment essential for electron transport. The engineered “unlocked” architecture not only imparts hydrophilicity to the inherently hydrophobic CNT surface but also maximizes the utilization of the dormant internal volume, substantially mitigating ion diffusion resistance. As direct quantitative evidence of this internal activation, the composite fibers exhibit a 11.2-fold enhancement in specific capacitance and superior rate performance compared to pristine CNT fibers, confirming the efficient penetration of ions into the deep core. Ultimately, this study demonstrates a robust methodology for activating the dormant surfaces of dense 1D nanomaterial assemblies without compromising the intrinsic CNT structure or requiring complex active material hybrids, thereby establishing a universal design paradigm for next-generation composite materials requiring dynamic ion transport. TOC: A lyotropic liquid crystalline co-assembly strategy widens interstitial channels to drive comprehensive electrolyte penetration, activating dormant 1D nanomaterial surfaces without compromising their intrinsic structural integrity.