S. Panero

A laboratory-scale lithium-ion battery recycling process

After reviewing the status of the lithium battery waste treatment and, in particular, outlining the technical and practical aspects of this operation, we describe some preliminary activity in progress in our laboratory mainly directed to the development and evaluation of a multi-step recycling process. Although this process is still in an exploratory phase, the preliminary results obtained in our laboratory suggest that the process may be of some practical interest since it gives promises of obtaining a good recovery of the battery components by rather efficient and easily achievable operations.

An advanced lithium-ion battery based on a graphene anode and a lithium iron phosphate cathode.

We report an advanced lithium-ion battery based on a graphene ink anode and a lithium iron phosphate cathode. By carefully balancing the cell composition and suppressing the initial irreversible capacity of the anode in the round of few cycles, we demonstrate an optimal battery performance in terms of specific capacity, that is, 165 mAhg(-1), of an estimated energy density of about 190 Wh kg(-1) and a stable operation for over 80 charge-discharge cycles. The components of the battery are low cost and potentially scalable. To the best of our knowledge, complete, graphene-based, lithium ion batteries having performances comparable with those offered by the present technology are rarely reported; hence, we believe that the results disclosed in this work may open up new opportunities for exploiting graphene in the lithium-ion battery science and development.

Progress in lithium polymer battery R&D

In this paper the characteristics and performance of composite polymer electrolytes formed by dispersing selected ceramic (e.g. γ-LiAlO2, Al2O3, SiO2) powders in poly(ethylene oxide)–lithium salt (e.g. PEO–LiCF3SO3) matrices, are reported and discussed. Particular emphasis is devoted to the role of these composite electrolytes in providing the conditions for stabilizing the interface with the lithium metal electrode, as well as for enhancing the electrolyte’s overall transport properties. Finally, results based on tests of practical prototypes demonstrate that these unique properties allow the development of new types of high performance, rechargeable lithium polymer batteries.

A New, Safe, High‐Rate and High‐Energy Polymer Lithium‐Ion Battery

Adv. Mater. 2009, 21, 4807–481

The role of conductive polymers in advanced electrochemical technology

Abstract The properties of selective examples of ionically conducting polymers are reported and discussed in view of their application in advanced design, rechargeable batteries and in laminated electrochromic devices.

Microbial reductive dechlorination of trichloroethene to ethene with electrodes serving as electron donors without the external addition of redox mediators.

In situ bioremediation of industrial chlorinated solvents, such as trichloroethene (TCE), is typically accomplished by providing an organic electron donor to naturally occurring dechlorinating populations. In the present study, we show that TCE dechlorinating bacteria can access the electrons required for TCE dechlorination directly from a negatively polarized (−450 mV vs. SHE) carbon paper electrode. In replicated batch experiments, a mixed dechlorinating culture, also containing Dehalococcoides spp., dechlorinated TCE to cis‐dichloroethene (cis‐DCE) and lower amounts of vinyl chloride (VC) and ethene using the polarized electrode as the sole electron donor. Conversely, neither VC nor ethene formation occurred when a pure culture of the electro‐active microorganism Geobacter lovleyi was used, under identical experimental conditions. Cyclic voltammetry tests, carried out on the filter‐sterilized supernatant of the mixed culture revealed the presence of a self‐produced redox mediator, exhibiting a midpoint potential of around −400 mV (vs. SHE). This yet unidentified redox‐active molecule appeared to be involved in the extracellular electron transfer from the electrode to the dechlorinating bacteria. The ability of dechlorinating bacteria to use electrodes as electron donors opens new perspectives for the development of clean, versatile, and efficient bioremediation systems based on a controlled subsurface delivery of electrons in support of biodegradative metabolisms and provides further evidence on the possibility of using conductive materials to manipulate and control a range of microbial bioprocesses. Biotechnol. Bioeng. 2009;103: 85–91.

Rechargeable Li / Li1 + x V 3 O 8 Cells

Murphy et al., (1981) and Abraham et al., (1981) have investigated the possibility of a use of transition metal oxides as substitutes of TiS2 in cathodes for rechargeable Li cells, giving particular attention to the V compounds of formula V6O(13+y) with y less than 0.2. The considered materials have greater energy densities than TiS2. However, an important drawback is reported for both V6O13.16 (nonstoichiometric). At 1.6 V a reduction process occurs which inhibits further rechargeability. This phenomenon is probably related to irreversible structure reorganizations connected with the high Li(+) content. In connection with the present investigation, it has been attempted to overcome the considered drawback by using a material, which while retaining the basic electrochemical features of V6O(13+y), would be able to undergo overdischarges without strucural damage. The use of Li(1+x)V308 has been investigated in this connection.

Characterization of an electro-active biocathode capable of dechlorinating trichloroethene and cis-dichloroethene to ethene

In the presence of suitable electron donors, the industrial solvent trichloroethene (TCE) is reductively dechlorinated by anaerobic microorganisms, eventually to harmless ethene. In this study we investigated the use of a carbon paper electrode, polarized to -550 mV vs. standard hydrogen electrode (SHE), as direct electron donor for the mediator-less microbial reductive dechlorination of TCE to ethene. In potentiostatic batch assays, TCE was dechlorinated to predominantly cis-dichloroethene (cis-DCE) and lower amounts of vinyl chloride (VC) and ethene, at rates falling in the range 14.2-22.4 micro equiv./Ld. When cis-DCE was spiked to the system, it was also dechlorinated, to VC and ethene, but at a much lower rate (1.5-1.7 micro equiv./Ld). Scanning electron microscopy and FISH analyses revealed that the electrode was homogeneously colonized by active bacterial cells, each in direct contact with the electrode surface. Cyclic voltammetry tests revealed the presence, at the electrode interface, of formed redox active components possibly involved in the extracellular electron transfer processes, that were however detached by a vigorous magnetic stirring. Electrochemical impedance spectroscopy (EIS) tests revealed that polarization resistances of the electrode in the presence of microorganisms (ranging from 0.09 to 0.17 k Omega/cm(2)) were one-order of magnitude lower than those measured with abiotic electrodes (ranging from 1.4 to 1.8 k Omega/cm(2)). This confirmed that attached dechlorinating microorganisms significantly enhanced the kinetics of the electron transfer reactions. Thus, for the first time, the bio-electrochemical dechlorination of TCE to ethene is obtained without the apparent requirements for exogenous or self-produced redox mediators. Accordingly, this work further expands the range of metabolic reactions and microorganisms that can be stimulated by using solid-state electrodes, and has practical implications for the in situ bioremediation of groundwater contaminated by chlorinated solvents.

Proton Polymeric Gel Electrolyte Membranes Based on Polymethylmethacrylate

In this work we report the synthesis of proton-conducting gel membranes obtained by incorporating salicylic acid in a highly plasticized (poly)methylmethacrylate matrix. We have prepared these gel membranes by using particular solvent mixtures consisting of propylene carbonate (PC), ethylene carbonate (EC), and fixed molar ratios of either dimethylformamide (DMF), methylformamide (MF), or formamide (F). The conductivity of the gel membranes prepared from these three-solvent mixtures is higher than that obtained by the parent liquid PC/EC solutions. Furthermore, the membranes are stable at moderately high temperatures (not exceeding 70°C), and their conductivity is only moderately dependent on the relative humidity conditions.

A Safe, Low-Cost, and Sustainable Lithium-Ion Polymer Battery

A polymer lithium-ion battery, formed by a Li 4/3 Ti 5/3 O 4 -LiFePO 4 electrode combination and a poly(vinylidene fluoride) (PVdF)-based gel electrolyte, is presented and discussed. The electrochemical characterization demonstrates that this battery is capable of delivering appreciable capacity values at rates ranging from C/32 (160 mAh g -1 ) to 0.75C (130 mAh g -1 ), this being accompanied by a remarkable cycle life. In addition, because the two electrodes are based on common and nontoxic materials and operate within the stability window of the electrolyte, the battery is expected to be safe, inexpensive, and compatible with the environment. All these properties make the battery of prospective interest for application in the hybrid and electric vehicle field.