Multifunctional, robust, light-weight, free-standing MWCNT/phenolic composite paper as anodes for lithium ion batteries and EMI shielding material

Abstract

Energy density of Li-ion batteries is marred due to the additional weight of copper, which is used as a current collector. In this work, fabrication of strong, graphitized, multiwalled carbon nanotubes (G-CNTs)/phenolic composite paper using a new dispersion technique is reported. The composite paper has been used as a free-standing current collector, as well as an anode material for Li-ion batteries, because of its good electrical conductivity of 76 S cm⁻¹. This highly thin conductive composite paper (thickness 140 μm) also shows efficient electromagnetic interference (EMI) shielding effectiveness of 32.4 dB in Ku-band (12.4–18 GHz). Moreover, structural and morphological studies were carried out using TEM and SEM. The flexural strength of the composite paper was 30 MPa, which is good enough for use as an electrode in batteries. The electrochemical properties of the composite paper were investigated by galvanostatic charge–discharge test. It exhibits a stable reversible specific capacity for more than 45 cycles. EMI shielding effectiveness (SE) was measured using a vector network analyzer, and the total EMI-SE surpasses the value needed for commercial applications.