Cinzia Cento

Lithium-ion batteries based on titanium oxide nanotubes and LiFePO 4

In this paper, the morphology, the conformation, and the electrochemical performance of TiO2 nanotubes and LiFePO4 have been studied by using scanning electron microscope, XRD, and charge/discharge cycles. The electrochemical tests comprised low rate cycling, cycling at C rate, and cycling at different rates. This work was finalized to the fabrication of lithium-ion batteries based on the TiO2/LiFePO4 redox couple. Battery cells were assembled and electrochemical tests were performed to evaluate cell capacity, power, and energy. Further tests were carried out to evaluate the capacity retention as a function of cycle number and discharge current.

Steam Hydrolysis of Lithium Hydride

Steam hydrolysis of lithium hydride was studied at various temperatures (20°C–80°C). To monitor the reaction rate, hydrogen flow was recorded as a function of time. Phase composition of the reaction products was analyzed by XRD spectroscopy. A variation in the reaction mechanism was found for temperatures lower than 70°C when lithium hydride was reduced to 10% of the initial amount. Using XRD analysis it was found that the main product obtained at temperatures ranging from 20°C to 70°C was LiOH.H2O. By increasing the temperature, the percentage of dehydrate slowly increases, and at 80°C the dehydrate represents the main product. A simple model for steam hydrolysis of lithium hydride is proposed taking into consideration the experimental results. The behavior of hydrogen flow was related to water vapor pressure and unreacted lithium hydride amount. The change in the reaction mechanism was related to a variation of water uptake (from the solid phase to the gas phase) to the lithium hydride surface.

Preparation of a composite anode for lithium-ion battery using a commercial water-dispersible non-fluorinated polymer binder

This paper describes a method for the preparation of a composite anode for lithium ion-battery using a commercial non-fluorinated water-dispersible polymer (Pattex PL50) as a binder. The benefits offered by using this polymer are related to its low cost and negligible toxicity. Furthermore, since the polymer is water dispersible, its adoption allows to replace the organic solvents, traditionally used in lithium-ion battery technology, with water thus decreasing the hazardousness of the preparation process as well as the production costs of the electrodes. In this paper, the preparation, characterization, and electrochemical properties of electrodes using the Pattex PL50 as the binder are described. A commercial high-capacity mesocarbon microbead graphite was selected as the electrode active material.

Characterization of mixtures of sodium iron (II)/iron (III) phosphate as cathodes for sodium batteries

Sodium iron (II) phosphate/iron (III) phosphate mixtures with different Fe(II)/Fe(III) ratio were synthesized. X-ray diffraction, scanning electron micrographs, and thermal analysis were employed to characterize the samples. The electrochemical properties of electrodes prepared by using the samples as the active material were evaluated in lithium cells. One of the samples was electrochemical tested in sodium cells. The cell cyclability was evaluated as a function of the discharge rate. The values of capacity and voltage were employed for the calculation of the specific discharge energy and power.

Fabrication and characterization of composite electrodes for lithium-ion batteries

This paper reports the preparation and the characterization of composite electrodes based on TiO2 and LiFePO4. The electrodes were studied by using XRD, SEM, and charge/discharge cycles. The electrochemical tests comprised low rate cycling and cycling at different rates. The electrodes were used for the fabrication of lithium-ion batteries. Battery cells were assembled and electrochemical tested at various discharge rates to evaluate cell capacity and capacity retention as a function of the discharge rate.

A synthesis of LiFePO4 starting from FePO4 under reducing atmosphere

A fast and easy way to produce LiFePO 4 starting from FePO 4 , used as iron and phosphorus source, is proposed. 5% hydrogen is employed as a reducing agent and various compounds containing lithium as lithiation agents. The selected lithiation agents included: LiCl, CH 3 COOLi , LiOH, Li 2 S , LiH, and Li 2 CO 3 . Solid state synthesis is used for the LiFePO 4 preparation and the so obtained materials are structurally characterized by XRD. The materials are used to fabricate composite electrode and their specific capacity is evaluated by low rate galvanostatic charge/discharge cycles (C/10 rate). Among the various lithium salts, the acetate give rise to the LiFePO 4 with the best electrochemical performance. The morphology of this material is further investigated by SEM microscopy and the specific capacity is evaluated as a function of the discharge rate and the cycle number.

A synthesis of LiFePO4starting from FePO4under reducing atmosphere

A fast and easy way to produce LiFePO 4 starting from FePO 4 , used as iron and phosphorus source, is proposed. 5% hydrogen is employed as a reducing agent and various compounds containing lithium as lithiation agents. The selected lithiation agents included: LiCl, CH 3 COOLi , LiOH, Li 2 S , LiH, and Li 2 CO 3 . Solid state synthesis is used for the LiFePO 4 preparation and the so obtained materials are structurally characterized by XRD. The materials are used to fabricate composite electrode and their specific capacity is evaluated by low rate galvanostatic charge/discharge cycles (C/10 rate). Among the various lithium salts, the acetate give rise to the LiFePO 4 with the best electrochemical performance. The morphology of this material is further investigated by SEM microscopy and the specific capacity is evaluated as a function of the discharge rate and the cycle number.

A synthesis of LiFePO{sub 4} starting from FePO{sub 4} under reducing atmosphere

A fast and easy way to produce LiFePO 4 starting from FePO 4 , used as iron and phosphorus source, is proposed. 5% hydrogen is employed as a reducing agent and various compounds containing lithium as lithiation agents. The selected lithiation agents included: LiCl, CH 3 COOLi , LiOH, Li 2 S , LiH, and Li 2 CO 3 . Solid state synthesis is used for the LiFePO 4 preparation and the so obtained materials are structurally characterized by XRD. The materials are used to fabricate composite electrode and their specific capacity is evaluated by low rate galvanostatic charge/discharge cycles (C/10 rate). Among the various lithium salts, the acetate give rise to the LiFePO 4 with the best electrochemical performance. The morphology of this material is further investigated by SEM microscopy and the specific capacity is evaluated as a function of the discharge rate and the cycle number.