Central Laboratory of Batteries And Cells

Poznan, Poland

Central Laboratory of Batteries And Cells

Poznan, Poland
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Acznik I.,Central Laboratory of Batteries And Cells | Lota K.,Central Laboratory of Batteries And Cells
Journal of Solid State Electrochemistry | Year: 2017

Combining the advantages of lithium-ion batteries and supercapacitors is an interesting solution to high-energy devices with the maintenance of high power output. Herein we report on the performance of the lithium-ion capacitors (LICs), exploiting graphene-based materials and activated carbon as negative and positive electrodes, respectively. The electrochemical properties of pre-lithiated reduced graphite oxides (reduced thermally—TRGO, or chemically—CRGO) and pristine graphite are compared based on measurements conducted in two- and three-electrode cells. Chemically reduced graphite oxide (CRGO) displays excellent performance at current densities up to 8 A g−1. The assembled hybrid capacitor delivers the energy density around 80 Wh kg−1 along a wide range of power densities. Promising results show that even at power value of 24.8 kW kg−1, the device retains energy density over 35 Wh kg−1. The cycle performance also shows good energy retention comparing with a graphite anode. However, better energy retention is observable for the TRGO-negative electrode material. After the 2000 of cycles, the AC/TRGO(Li) system loaded with the current density of 1 A g−1 provides energy of 58 Wh kg−1. [Figure not available: see fulltext.] © 2017 Springer-Verlag GmbH Germany

Acznik I.,Central Laboratory of Batteries And Cells | Lota K.,Central Laboratory of Batteries And Cells | Sierczynska A.,Central Laboratory of Batteries And Cells
MRS Communications | Year: 2017

Lithium-ion capacitors utilizing graphite (G) and reduced graphite oxide (RGO) as negative electrode materials were investigated. Various reduction methods of graphite oxide were applied to compare properties of modified materials. The hybrid cells showed the energy density at mild current regimes of ca. 70–100 Wh/kg. However, at higher rates, only the capacitor with chemically RGO maintained this tendency. Moreover, the system demonstrated the energy density of 34 Wh/kg at a power density of 26 kW/kg. The electrochemical measurements were conducted in three-electrode systems to record responses of positive and negative electrodes separately. Copyright © Materials Research Society 2017

Urbaniak J.,Poznan University of Technology | Skowronski J.M.,Poznan University of Technology | Olejnik B.,Central Laboratory of Batteries And Cells
Journal of Solid State Electrochemistry | Year: 2010

In the present work, a simple method of preparation of FeCl 4 -- graphite intercalation compounds from HCl/FeCl 3 solution with the aid of chemical oxidant is presented. Based on X-ray diffraction measurements it was concluded, that stages 8, 6, and 5 FeCl 4 --graphite intercalation compounds were obtained. The compounds thus obtained were thermally treated to obtain Fe 2O 3-exfoliated graphite composites. The dispersion of Fe 2O 3 in the exfoliated graphite flakes was examined with the aid of the energy dispersive X-ray analysis combined with a scanning electron microscopy. Electrochemical behavior of electrodes was investigated in 6 M KOH solution. Electrochemical investigations proved the formation of FeOOH on the surface of exfoliated graphite during the anodic process. Besides, electrochemical investigations showed that the lower limit potential strongly affects the redox behavior of the Fe 2O 3-EG electrode. © Springer-Verlag 2010.

Sierczynska A.,Central Laboratory of Batteries And Cells | Lota K.,Central Laboratory of Batteries And Cells | Lota G.,Central Laboratory of Batteries And Cells | Lota G.,Poznan University of Technology
Journal of Power Sources | Year: 2010

Nickel hydroxide is used as an active material in positive electrodes of rechargeable alkaline batteries. The capacity of nickel-metal hydride (Ni-MH) batteries depends on the specific capacity of the positive electrode and utilization of the active material because of the Ni(OH)2/NiOOH electrode capacity limitation. The practical capacity of the positive nickel electrode depends on the efficiency of the conductive network connecting the Ni(OH)2 particle with the current collector. As β-Ni(OH) 2 is a kind of semiconductor, the additives are necessary to improve the conductivity between the active material and the current collector. In this study the effect of adding different carbon materials (flake graphite, multi-walled carbon nanotubes (MWNT)) on the electrochemical performance of pasted nickel-foam electrode was established. A method of production of MWNT special type of catalysts had an influence on the performance of the nickel electrodes. The electrochemical tests showed that the electrode with added MWNT (110-170 nm diameter) exhibited better electrochemical properties in the chargeability, specific discharge capacity, active material utilization, discharge voltage and cycling stability. The nickel electrodes with MWNT addition (110-170 nm diameter) have exhibited a specific capacity close to 280 mAh g-1 of Ni(OH)2, and the degree of active material utilization was ∼96%. © 2010 Elsevier B.V.

Lota G.,Poznan University of Technology | Tyczkowski J.,Technical University of Lodz | Kapica R.,Technical University of Lodz | Lota K.,Central Laboratory of Batteries And Cells | Frackowiak E.,Poznan University of Technology
Journal of Power Sources | Year: 2010

The carbon material was modified by RF plasma with various reactive gases: O2, Ar and CO2. Physicochemical properties of the final carbon products were characterized using different techniques such as gas adsorption method and XPS. Plasma modified materials enriched in oxygen functionalities were investigated as electrodes for supercapacitors in acidic medium. The electrochemical measurements have been carried out using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy. The electrochemical measurements have confirmed that capacity characteristics are closely connected with a type of plasma exposition. Modification processes have an influence on the kind and amount of surface functional groups in the carbon matrix. The moderate increase of capacity of carbon materials modified by plasma has been observed using symmetric two-electrode systems. Whereas investigations made in three-electrode system proved that the suitable selection of plasma modification parameters allows to obtain promising negative and positive electrode materials for supercapacitor application. © 2009 Elsevier B.V.

Lota G.,Poznan University of Technology | Lota G.,Central Laboratory of Batteries And Cells | Milczarek G.,Poznan University of Technology
Electrochemistry Communications | Year: 2011

Two types of carbonaceous materials of different specific surface areas (835 and 1901 m2 g-1) were used as electrode materials in electrochemical capacitors and their performance was investigated in 1 mol L-1 H2SO4 with and without addition of two lignosulfonates of different molecular masses (8000 and 42,700 g mol -1). Measurements of 2-electrode cells confirmed that lignosulfonates as electrolyte additives increase the overall capacity of the supercapacitor of up to 33%. Moreover, for the electrolyte with lignosulfonates the charge propagation was facilitated, implying its capability of working at heavy duty regimes. Cycleability tests confirmed the absence of any significant effect of lignosulfonate additions to the electrolyte on supercapacitor durability. The relative capacitance change after 5000 cycles of galvanostatic charge/discharge at 1 A g-1 was ca. + 4.5% for less porous carbon and - 4.2% for more porous carbon, respectively. Furthermore, the investigations carried out in a 3-electrode configuration proved that a lignosulfonate addition to the electrolyte gives rise to the development of a reversible redox system on the positive electrode, due to the deposition of a thin lignosulfonate-derived film showing substantial redox activity assignable to quinone-type moieties. © 2011 Elsevier B.V.

Walkowiak M.,Central Laboratory of Batteries And Cells
International Journal of Electrochemical Science | Year: 2011

It has been demonstrated that pre-treatment (impregnation) of graphite anodes in a polyether functionalized disiloxane agent prevents graphite flake exfoliation and electrode degradation in Li-ion cells with electrolytes based on propylene carbonate (PC) as single electrolyte solvent. This beneficial effect has been evidenced to strongly depend on the concentration of the impregnation bath. For 100% concentration (pure siloxane), SEM images do not exhibit visible signs of flake splitting and the corresponding galvanostatic charge/discharge curves exhibit conventional lithium intercalation behavior, with reversible capacity approaching 300 mAh g-1. Post-mortem EDX analysis of cycled electrodes revealed the presence of silicon species in the passive layers on graphite. The proposed approach can be regarded as alternative for conventional exfoliation-suppressing methods relying on bulk electrolyte additives. © 2011 by ESG.

Wasinski K.,Central Laboratory of Batteries And Cells | Walkowiak M.,Central Laboratory of Batteries And Cells | Lota G.,Central Laboratory of Batteries And Cells | Lota G.,Poznan University of Technology
Journal of Power Sources | Year: 2014

Novel electrolyte additive for electrochemical capacitors has been reported. It has been demonstrated for the first time that addition of humic acids (HA) to KOH-based electrolyte significantly increases capacitance of symmetrical capacitors with electrodes made of activated carbon. Specific capacitances determined by means of galvanostatic charge/discharge, cyclic voltammetry and electrochemical impedance spectroscopy consistently showed increases for HA concentrations ranging from 2% w/w up to saturated solution with maximum positive effect observed for 5% w/w of the additive. The capacitance increase has been attributed to complex faradaic processes involving oxygen-containing groups of HA molecules. Due to abundant resources, low cost and easy processability the reported solution can find application in electrochemical capacitor technologies. © 2014 Elsevier B.V. All rights reserved.

Zalewska A.,Warsaw University of Technology | Walkowiak M.,Central Laboratory of Batteries And Cells | Niedzicki L.,Warsaw University of Technology | Jesionowski T.,Poznan University of Technology | Langwald N.,Warsaw University of Technology
Electrochimica Acta | Year: 2010

The aim of the presented work was to perform a preliminary study of the physicochemical and interfacial properties of hybrid organic-inorganic gel electrolytes for Li-ion batteries based on the PVdF/HFP polymeric matrix and surface-modified silicas. Two types of silica fillers of different grain sizes (>500 nm and ∼100 nm) were used as additives. The silica particles were modified by two different functional groups, i.e. methacryloxy and vinyl ones. The gel electrolytes based on PVdF/HFP copolymer were prepared according to the so-called Bellcore two-step process. The motivation of the present work was to study more deeply those systems in terms of morphology by means of scanning electron microscopy techniques. Fillers modified with identical functional groups but differing fundamentally in the manufacturing processes were compared in terms of the impact on morphology and electrochemical performance of the resulting membranes. Interfacial properties were examined by means of impedance spectroscopy technique using Swagelok-type cells with two lithium electrodes. © 2009 Elsevier Ltd. All rights reserved.

Grzeczka G.,Polish Naval Academy | Swoboda P.,Central Laboratory of Batteries And Cells
Solid State Phenomena | Year: 2015

The most commonly used starter batteries for ship engine rooms are lead acid systems. Lead acid batters have the lowest electrochemical parameters from all other modern electrochemical systems. On the other hand their biggest advantage is the price of the cell which is much lower comparing to other electrochemical systems. Due to fact that the lithium – ion batteries are very widely used and constantly developed this technology is starting to be promising as an alternative for lead acid batteries for starter applications. Because of this there is a need to verify if the lithium-ion technology can be used for start-up and power backup systems and how will it affect the construction of the engine room and those systems. In order to determine the potential energetic requirements during the design of starter systems in an backup engine room with the use of lithium – ion batteries, in the article the analytic of their performance was conducted with comparison of other electrochemical systems. © (2015) Trans Tech Publications, Switzerland.

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