Achieving monolithic electrode integration via chemically unified elastomeric current collectors for corrosion immune, high rate lithium-ion batteries

Fast charging lithium-ion batteries are increasingly limited by interfacial mechanical failure between electrodes and current collectors, which leads to contact degradation, impedance growth, and accelerated performance decay under repeated electrochemical cycling. This work reports a chemically continuous and mechanically adaptive current collector architecture that addresses this overlooked bottleneck through the integration of polymethyl methacrylate-grafted natural rubber (MG30) and multi-walled carbon nanotubes (MWCNTs). The polar polymethyl methacrylate (PMMA) segments promote induced dipole interactions with the nanotube network, enabling the formation of a homogeneous conductive framework that combines high electrical conductivity with mechanical compliance. More importantly, the use of MG30 as both the current-collector matrix and electrode binder establishes a chemically continuous interface across the electrode-collector junction, resulting in enhanced adhesion, reduced interfacial resistance, and improved tolerance to cycling-induced stress accumulation. Unlike conventional aluminum current collectors, the elastomeric architecture exhibits intrinsic resistance to fluoride-induced corrosion while maintaining structural integrity during long-term operation. Consequently, lithium iron phosphate (LiFePO₄, LFP)||Li cells deliver stable high-rate performance and exceptional cycling durability, sustaining 4000 cycles at 10 C and retaining 80.3% capacity after 2000 cycles. The architecture further demonstrates compatibility with high mass loading electrodes and flexible pouch-cell configurations.