F. La Mantia

Nickel Hexacyanoferrate as Suitable Alternative to Ag for Electrochemical Lithium Recovery

Currently, Li is mainly produced through evaporation of Li-rich brines obtained from South American countries such as Bolivia, Chile, and Argentina. The most commonly used process, the lime-soda evaporation, requires a long time and several purification steps, which produces a considerable amount of chemical waste. Various electrochemical methods have been proposed as alternatives, but they use expensive metals such as Ag or Pt, thus rendering these methods economically unacceptable. In this work, we present KNiFe(CN)6 , an abundant and environmentally friendly material, as alternative to these expensive components. The Prussian blue derivate has a higher affinity toward cations (Na(+) or K(+) ) than for Li(+) . Additionally, the use of KNiFe(CN)6 permits the utilization of seawater or brine water as recovery solution, thus reducing the consumption of fresh water, which is typically a scarce element in Li production sites.

Solid electrolyte interphase in semi-solid flow batteries: a wolf in sheep's clothing

The formation of the alkyl carbonate-derived solid electrolyte interphase (SEI) enables the use of active materials operating at very cathodic potentials in Li-ion batteries. However, the SEI in semi-solid flow batteries results in a hindered electron transfer between a fluid electrode and the current collector restricting the operating potentials to ca. 0.8 V vs. Li/Li(+) for EC-based electrolytes.

Capacitive mixing and mixing entropy battery

Abstract The ‘capacitive mixing’ (CapMix) and ‘mixing entropy battery’ (MEB) techniques belong to a class of SGP processes (AccMix) based on a couple of electrodes dipped in a cell, in which two feed solutions with different salinities are alternately injected. The electrodes constitute an accumulator of electrical charge; they are charged in one of the feed solutions and discharged in the other. Due to the variation of the electrode potentials induced by the salinity change, the charge is extracted from the cell at a higher voltage than that applied during the charging phase. This results in a production of energy at the expense of the salinity difference; the solution mixing is mediated by the temporary storage of the salt inside the electrodes. In this chapter, the state of the art of this class of processes is presented, along with the main R&D achievements and future perspectives for further development.

Understanding memory effects in Li-ion batteries: evidence of a kinetic origin in TiO2 upon hydrogen annealing

Memory effects in Li-ion battery materials have been explained on the basis of the thermodynamics of many-particles body, however the role of the (de-)intercalation kinetics is not yet clear. We demonstrate that kinetic aspects, specifically Li-ion mobility, are determining the magnitude of the memory effect in TiO2 by studying samples with different levels of oxygen vacancies.