Superconducting BSCCO Ceramics as Additive to the Zinc Electrode Mass in the Rechargeable Nickel-Zinc Batteries

The electronic conductivity of the main component of the zinc electrode in the rechargeable zinc-nickel battery – ZnO,  is rather poor and this is the main reason for the electrochemical heterogeneity of the anode mass and the loss of active surface area during charge/discharge cycling with a corresponding negative effect on the electrode characteristics In the present work, the possibility of application of superconductive cuprate Bi-Pb-Sr-Ca-Cu-O (BSCCO) ceramic as a multifunctional conductive additive to the zinc electrode mass is studied. Powder samples of the BSCCO ceramic Bi1,7Pb0,3Sr2Ca2Cu3Ox are produced by two-stage solid-state synthesis and they are physicochemically characterized. The XRD patterns and SEM observation reveal a well crystallized single phase of superconducting 2212 BSCCO system with average crystallite size 5-10 µm. The chemical stability of BSCCO ceramics in highly alkaline medium of the Ni-Zn battery is confirmed by structural and morphological analysis (XRD, SEM and EDX) of the samples before and after prolong exposure (96 h) to 7M KOH. The electrochemical tests are carried out by a specially designed prismatic alkaline Ni-Zn battery cell with conventional sintered type nickel electrodes and pasted zinc electrode with active electrode mass based on ZnO (88 wt.%) and addition of BSCCO powder or acetylene black as conductive additives. The study show that the zinc electrode with BSCCO superconducting ceramic additive exhibits very good cycleability, remarkable capacity stability and much higher discharge capacity at prolong charge/discharge cycling in comparison to the  zinc electrode with the “classic” carbon conductive additive. It is suggested that the addition of BSCCO ceramics improves not only conductivity of the electrode mass and reduces the gas evolution but also stabilizes porosity structure. The results obtained prove the possibility of application of superconducting BSCCO ceramics as a multifunctional additive to the active mass of the zinc electrodes for alkaline battery systems

Synthesis and electrochemical properties of the electrode materials for supercapacitors

New electrode materials for supercapacitors -activated carbons, produced by carbonization of mixtures of coal tar pitch and furfural, with a subsequent hydrothermal treatment, were characterized and tested electrochemically. The microstructure, surface morphology and porous structure of the carbon materials were studied, and the main textural parameters and micropore size distribution were determined. Symmetric sandwich-type supercapacitor cells, with identical carbon electrodes and organic electrolyte, were assembled and subjected to charge-discharge cycling study at different current rates. Four types of carbons as electrodes with different specific surface area (1000 -1600 m 2 g -1 ) and texture parameters, as well as tree types of organic electrolytes (Et 4 NBF 4 -PC, LiBF 4 -PC, LiPF 6 -DMC/EC), were tested and compared with an asymmetric supercapacitor, composed by graphitized-activated carbon (carbon foam) as a negative electrode, and activated carbon/Li 4 Ti 5 O 12 oxide composite as a positive electrode. The capacitance values of up to 75 F.g -1 were obtained for the symmetric supercapacitors, depending on the microstructure and the conductivity of the carbon material, and about two times higher capacitance was obtained for the asymmetric supercapacitor, with good cycleability of both supercapacitor systems