Synthesis of self-healing polyurethane and its application in graphene/SnO₂-pillared carbon anode materials

Abstract

Self-healing polyurethane (SHPU) containing disulfide was synthesized and used as a binder to investigate its effect on the performance of reduced graphene oxide–tin oxide electrodes compared to those of polyurethane (PU) and poly(vinylidene difluoride) (PVDF) binders in Li-ion battery (LIB). Structural and morphological characterization of the SHPU and electrode was performed using a tensile tester, Fourier transform infrared spectroscopy, X-ray diffractometer, and scanning electron microscopy. Electrochemical performance was investigated using Galvanostatic charge–discharge and electrochemical impedance measurements. The tensile properties and scanning electron microscopy photographs confirmed the self-healing characteristics of the synthesized SHPU. Electrochemical studies were conducted using an RGO-SnO2 electrode. The electrochemical measurements revealed that the SnO2-pillared carbon-based anode materials with SHPU binder showed improved cycling performances with an excellent reversible capacity retention compared to PU or PVDF. After 1000 cycles at 1C, the surface morphology of the electrode with SHPU showed no cracks or dendrites, while the PVDF-based electrode possessed some cracks and dendrites on its surface. The electrochemical results confirmed that SHPU binder improves the electrochemical performance of LIBs.

A High-Performance Polyurethane–Polydopamine Polymeric Binder for Silicon Microparticle Anodes in Lithium-Ion Batteries

“…In the spectra of PU (Figure e,f), the peaks around 3336 cm –1 (N–H stretching) and 1716 cm –1 (CO stretching vibration) corresponded to the formation of urethane (NH–COO−), and the peaks at 1525 cm –1 and 1313 cm –1 are assigned to the N–H bending vibration (amide II band) and the C–N (amide III band) stretching vibration, respectively . The peaks at 2854 and 2923 cm –1 represent the −CH asymmetric stretching, which are consistent with the 1 H NMR results (Figure S3), wherein −(CH 2 ) n –CH 3 is located at around 0.86 and 1.09–1.3 ppm. , We prepared the PU–PDA binder by simply mixing PU with PDA. After mixture, the peak at around 3400 cm –1 is broadened, and especially, when the Si particles were added, the peak was shifted to the lower waves, proving the formation of hydrogen bonds between the components of the binder and the binder with the SiMPs.…”

“…31 The peaks at 2854 and 2923 cm −1 represent the −CH asymmetric stretching, which are consistent with the 1 H NMR results (Figure S3), wherein −(CH 2 ) n −CH 3 is located at around 0.86 and 1.09−1.3 ppm. 32,33 We prepared the PU−PDA binder by simply mixing PU with PDA. After mixture, the peak at around 3400 cm −1 is broadened, and especially, when the Si particles were added, the peak was shifted to the lower waves, proving the formation of hydrogen bonds between the components of the binder and the binder with the SiMPs.…”