From Volta’s pile to lithium ion battery: 200 years of energy

The aim of this paper is to provide a historical and scientific overview of the battery world, from the disrupting discovery of Alessandro Volta to the latest advances in lithium ion batteries. For sake of clarity, it has been divided into three parts: the past, the present and the future. The first part illustrates the historical path which led to the lithium ion batteries. The second part reports the main challenges to the Li ion batteries that have been and still must be faced for increasing their performance and their sustainability. In the last part, considerations about the future of lithium ion batteries are discussed, with a special focus on sustainability

A spectroelectrochemical study of copper chloro-complexes for high performance all-copper redox flow batteries

Redox Flow Batteries (RFB) are an ideal choice for large stationary applications. Among the different chemistries that can be exploited, all-copper aqueous RFB (CuRFB) use low-cost, earth-abundant raw materials with a well defined European supply chain. The CuRFB takes advantage of the three oxidation states of copper. As Cu(I) is not stable in aqueous media, the system is based on the chlorocomplexation of the copper cations. We demonstrated that it is possible to evaluate the complexation characteristic of the concentrated solutions used in CuRFB by investigating the speciation of copper (II) in electrolytes with increasing Cu(II) concentration. Spectroelectrochemical tests in diluted solution give information on the electrochemical behavior of electrolytes with a fare different chloro‑complexes distribution. Quantum chemical calculations elucidate the molecular structure and electronic transitions of water solvated copper chloro‑complexes, thus complementing the experimental picture

A robust, modular approach to produce graphene-MO X multilayer foams as electrodes for Li-ion batteries

Major breakthroughs in batteries would require the development of new composite electrode materials, with a precisely controlled nanoscale architecture. However, composites used for energy storage are typically a disordered bulk mixture of different materials, or simple coatings of one material onto another. We demonstrate here a new technique to create complex hierarchical electrodes made of multilayers of vertically aligned nanowalls of hematite (Fe 2 O 3 ) alternated with horizontal spacers of reduced graphene oxide (RGO), all deposited on a 3D, conductive graphene foam. The RGO nanosheets act as porous spacers, current collectors and protection against delamination of the hematite. The multilayer composite, formed by up to 7 different layers, can be used with no further processing as an anode in Li-ion batteries, with a specific capacity of up to 1175 μA h cm -2 and a capacity retention of 84% after 1000 cycles. Our coating strategy gives improved cyclability and rate capacity compared to conventional bulk materials. Our production method is ideally suited to assemble an arbitrary number of organic-inorganic materials in an arbitrary number of layers

Tuning Solid-State Photoluminescence Frequencies and Efficiencies of Oligomers Containing One Central Thiophene-S,S-dioxide Unit

We have synthesized thienylene- and phenylene-based oligomers displaying solid-state photoluminescence efficiencies up to 70% and photoluminescence frequencies which cover the entire visible range. All compounds contain one central nonaromatic thienyl-1,1-dioxide moiety in the main chain. The tuning of the light-emission frequency was achieved by progressively varying the degree of π−π electron delocalization between the nonaromatic moiety and the α-linked aromatic rings. All compounds displayed greater electron affinities than thienylene or phenylene oligomers of comparable lengths, as deduced from the reduction potentials measured by cyclic voltammetry

Multi-functional groups decorated composite nanofiber separator with excellent chemical stability in ester-based electrolyte for enhancing the lithium-ion transport

As various heat-resistant polymer separators come out, although they possess better thermal stability and superior affinity to liquid electrolyte than commercial polyolefin separator, the porous structure and chemical stability of these novel separators should be paid more attention. In this work, we prepare a thin polyacrylonitrile/cellulose acetate (PAN/CA) composite nanofiber separator and discuss the importance of chemical stability in the ester-based electrolyte. The addition of CA decreases the PAN/CA fiber diameter from 310 nm to 210 nm. However, CA containing a lot of ester groups is easy to be dissolved by liquid electrolyte for the property of similarity and compatibility. Hence, the obtained PAN/CA composite nanofiber separator is treated via alkaline hydrolysis process, and some ester groups are transformed to be hydroxyl groups. Noteworthily, hydroxyl-rich PAN/CA composite nanofiber separator not only remains stable in electrolyte, but also possesses an improved lithium-ion transport property for reducing concentration polarization effect. As a result, the LiCoO2/Li half cells employing the hydroxyl-rich composite nanofiber separator exhibits better capacity retention (118.5 mAh g -1 after 300 cycles) and superior rate performance (143.1 mAh g -1 at 3C). Therefore, this multi-functional groups decorated composite nanofiber separator with excellent chemical stability is a candidate for next-generation lithium-based battery

Chemically and thermally stable photo- and electroluminescent thiophene-based materials

We present a new class of thiophene-based oligomers and polymers with widely tunable photo and electroluminescence properties and which offer great potential for many different areas of application. We were able to synthesize materials displaying high solid-state fluorescence efficiency across the entire visible range. Electroactive polymers emitting light in the near IR were obtained by chemical and/or electrochemical polymerization of oligomers of different length. The polymers also displayed electrochromism, i.e. color change when electric current flowed through the material. All compounds were characterized by great thermo and photooxidative stability. With some of these materials efficient electroluminescent devices were fabricated and characterized

Copper chloro-complexes concentrated solutions: An electrochemical study

Basic studies on concentrated solutions are becoming more and more important due to the practical industrial and geological applications. The use in redox flow batteries is one of the most important applications of these solutions. Specifically, in this paper we investigated high-concentrated copper chloro-complexes solutions with different additives. The concentration of ligands and additives affects the physicochemical and electrochemical properties of 2 M solutions of Cu(I) and Cu(II). Solutions with calcium chloride and HCl as Cl- source were investigated with Cu:Cl ratios of 1:5 and 1:7, the 1:5 Cu:Cl ratio being the best performing. The substitution of calcium chloride with ammonium chloride increased the conductivity. However, while the effect on the positive electrode process was not very evident, the reversibility of the copper deposition-stripping process was greatly improved. Orthophosphoric acid could be a viable additive to decrease the complexation of calcium with chloride anions and to improve the stability of Cu(II) chloro-complexes. Absorption spectroscopy demonstrated that phosphate ions do not coordinate copper(II) but lead to a shift in the distribution of copper chloro-complexes toward more coordinated species. Electrochemically, the increased availability of chloride anions in solution stabilized the Cu(II)-rich solution and led to increased reversibility of the Cu(II)/Cu(I) redox process

Supercapacitive microbial fuel cell: Characterization and analysis for improved charge storage/delivery performance

© 2016 The Author(s) Supercapacitive microbial fuel cells with various anode and cathode dimensions were investigated in order to determine the effect on cell capacitance and delivered power quality. The cathode size was shown to be the limiting component of the system in contrast to anode size. By doubling the cathode area, the peak power output was improved by roughly 120% for a 10ms pulse discharge and internal resistance of the cell was decreased by ∼47%. A model was constructed in order to predict the performance of a hypothetical cylindrical MFC design with larger relative cathode size. It was found that a small device based on conventional materials with a volume of approximately 21cm3 would be capable of delivering a peak power output of approximately 25mW at 70mA, corresponding to ∼1300Wm−3