Nanofibrous cellulose as solid polymer electrolyte for lithium-ion battery applications.

Solid polymer electrolyte (SPE), which is composed of poly (vinylidenefluroride-co-hexafluoropropylene) (PVDF-HFP), lithium bis(oxalate) borate (LiBOB) salt and various concentrations of TiO2 as filler, has been prepared by solution casting technique. Structure, thermal and electrical properties of the SPE were examined using XRD and SEM, TG/DSC, and impedance spectroscopy, respectively. XRD analysis reveals amorphous nature of PVDF-HFP / LiBOB and TiO2 composite matrix. SEM photographs of polymer electrolyte membrane indicate good compatibility between polymer, salt, and other contents as well as amorphous phase formation in the fabricate of SPE. We obtained that (SPE) with composition of 70 wt% polymer, 28 wt% LiBOB and 2 wt% TiO2 has highest conductivity. XRD and DSC analysis indicate that the conductivity increases due to high amount of amorphous nature content. We suggest that the amorphous nature content may enhance segmental flexibility of polymeric chains and disordered structure of the electrolyte.

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Abstract. Lithium bis (oxalato) borate or LiBOB is potential candidate to substitute LiPF 6 which has many problems in lithium ion batteries. Many studies have been synthesized of electrolyte salt LiBOB to improve performance as electrolyte lithium ion batteries. In this paper we have studied the synthesis of compounds LiBOB undergoing pre-heat treatment in a vacuum. LiBOB was synthesized by mixing technical grade raw materials H2C2O4.2H2O, LiOH and H3BO3. The mixture H2C2O4.2H2O and LiOH was preheated at 60 °C for 2 h before adding H3BO3 in several time to be mortared in vacuum dryer, the mixture of the three starting materials was preheated in two steps at 70 °C for 6 h and the third step of preheating at a temperature of 100 °C. This powder was then characterized using XRD, FTIR and BET. The characterization results of LiBOB compared to commercial LiBOB powder. The XRD analysis results showed that the sample have formed LiBOB and LiBOB hydrate phase, while FTIR analysis results show the formation of functional groups of LiBOB. In addition, the BET results shows the surface area of synthesized LiBOB is 75.994 m 2 /g, close the surface area of commercial LiBOB, i.e 108.776 m 2 /g.