Reinforce the Adhesion of Gel Electrolyte to Electrode and the Interfacial Charge Transfer via In Situ Electrospinning the Polymeric Nanofiber Matrix

Abstract

The adhesion of a gel electrolyte to the electrode is one of the key factors to the electrochemical performance of lithium-ion batteries (LIBs). Herein, gel electrolyte is prepared on the LiFePO 4 electrode through in situ electrospinning the poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) nanofiber matrix, followed by lithium salt solution loading. The interfacial interactions between the in situ electrospun PVdF-HFP matrix and LiFePO 4 electrode before and after gelation are studied using dynamic thermomechanical analysis and scanning electron microscopy. The results demonstrate that the as-prepared gel electrolyte can adhere tightly onto the LiFePO 4 electrode. LIBs (half coin cells) are assembled using the as-obtained gel electrolyte to evaluate their electrochemical properties. The results show that the lithium-ion and electron transfer rates crossing the interface between gel electrolyte and LiFePO 4 electrode are enhanced. The electrochemical performances of the half coin cells, including specific capacity, rate capability, and cycle stability, are improved significantly.

Core–Shell PMIA@PVdF-HFP/Al2O3 Nanofiber Mats In Situ Coaxial Electrospun on LiFePO4 Electrode as Matrices for Gel Electrolytes

“…In Situ Coaxial Electrospinning Processes. The LiFePO 4 electrode was prepared following a conventional procedure that we described previously 33 and used as the collector during electrospinning of the nanofiber mats. To get the PVdF-HFP/Al 2 O 3 precursor solution, first, 0, 5, 10, and 15% Al 2 O 3 nanoparticles (relative to the weight of PVdF-HFP) were uniformly dispersed in a mixture of 12 mL of acetone and 4.27 mL of DMF solvents.…”

“…32 Actually, we prepared previously the poly-(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) gel electrolyte in situ on the LiFePO 4 electrode through electrospinning of the PVdF-HFP matrix, followed by lithium salt solution loading. 33 In comparison with the gel electrolyte based on the freestanding PVdF-HFP membrane, the in situ electrospun one showed enhanced electrochemical performance due most probably to the manifest adhesion force between the gel electrolyte and the LiFePO 4 electrode. Besides, it was illustrated that the interface interaction of the gel electrolytes to the electrode surface and even their electrochemical properties could also be enhanced by the incorporation of Al 2 O 3 , 34−37 nanoparticles within the polymeric matrices of the gel electrolytes.…”

“…It was reported that the membranes based on polymeric nanofiber mats generated through in situ electrospinning on the electrode surface showed usually improved interface interaction . Actually, we prepared previously the poly­(vinylidene fluoride- co -hexafluoropropylene) (PVdF-HFP) gel electrolyte in situ on the LiFePO 4 electrode through electrospinning of the PVdF-HFP matrix, followed by lithium salt solution loading . In comparison with the gel electrolyte based on the freestanding PVdF-HFP membrane, the in situ electrospun one showed enhanced electrochemical performance due most probably to the manifest adhesion force between the gel electrolyte and the LiFePO 4 electrode.…”

Critical advances in re-engineering the cathode-electrolyte interface in alkali metal-oxygen batteries

“…Nitrogen doping can greatly improve the electrochemical and catalytic performance of carbon materials. Ma et al [73] prepared a nitrogen-doped cathode structure with high porosity through a typical synthesis method. In the SEM images, the pure carbon material showed a massive structure, while the nitrogen-doped carbon showed a plicate sheet structure with pores.…”

Progress and perspectives on electrospinning techniques for solid‐state lithium batteries

“…Through the electrospinning technique, the preparation of PVDF-HFP fibrous gel electrolyte can be achieved directly on the LiFePO 4 electrode (Figure 12A), which is used as the acceptor. 119 Different from the previous GPEs that were usually fabricated as an isolated membrane, the in situ electrospinning preparation strategy achieves a significantly improved interfacial adhesion of polymer matrix and electrodes. The dynamic thermomechanical analysis reveals that the adhesive force between the in situ electrospun PVDF-HFP matrix and the LiFePO 4 electrode is 2.74 mN, while that for the mechanically mounted one is 2.25 mN.…”