RESUMEN

First-principles calculations within DFT have been performed to investigate the use of a recently synthesized form of silicene, the dumbbell (DB) silicene as an anode material for Li-ion batteries (LiBs). The energetically most stable geometries for Li adsorption on DB silicene were investigated, and the energy barriers for Li-ion diffusion among the possible stable adsorption sites were calculated. We found that DB silicene can be lithiated up to a ratio of 1.05 Li per Si atom, resulting in a high storage capacity of 1002 mA h g-1 and an average open-circuit potential of 0.38 V, which makes DB silicene suitable for applications as an anode in LiBs. The energy barrier for Li-ion diffusion was calculated to be as low as 0.19 eV, suggesting that the Li ions can easily diffuse on the entire DB silicene surface, decreasing the time for the charge/discharge process of the LiBs. Our detailed investigations show that the most stable form of two-dimensional silicon has characteristic features suitable for application in high-performance LiBs.

RESUMEN

In the last few years, the growing demand for electric vehicles (EVs) in the transportation sector has contributed to the increased use of electric rechargeable batteries. At present, lithium-ion (Li-ion) batteries are the most commonly used in electric vehicles. Although once their storage capacity has dropped to below 80-70% it is no longer possible to use these batteries in EVs, it is feasible to use them in second-life applications as stationary energy storage systems. The purpose of this study is to present an embedded system that allows a Nissan® LEAF Li-ion battery to communicate with an Ingecon® Sun Storage 1Play inverter, for control and monitoring purposes. The prototype was developed using an Arduino® microcontroller and a graphical user interface (GUI) on LabVIEW®. The experimental tests have allowed us to determine the feasibility of using Li-ion battery packs (BPs) coming from the automotive sector with an inverter with no need for a prior disassembly and rebuilding process. Furthermore, this research presents a programming and hardware methodology for the development of the embedded systems focused on second-life electric vehicle Li-ion batteries. One second-life battery pack coming from a Nissan® Leaf and aged under real driving conditions was integrated into a residential microgrid serving as an energy storage system (ESS).

RESUMEN

Li-ion batteries are daily present in our electronic devices. These batteries are used in electric and hybrid vehicles supporting the current agreements to decrease greenhouse gas emissions. As a result, the electric vehicle demand has increased in the world. As Li-ion batteries are composed of critical metals in which there is a risk of interruption of supply in the medium term, recycling is the key to a sustainable future without internal combustion vehicles. Understanding the current scenario and future perspectives is important for strategies of new battery design, recycling routes and reverse logistics, as well as policies for sustainable development. This paper presents an overview of current and future vehicles used worldwide. An increase from 1.3 to 2 billion vehicles is expected worldwide until 2030; an outstanding demand will occur mainly in BRICS countries. The data demonstrated a correlation between the number of vehicles in use and GDP. Patents and processes designed for recycling Li-ion batteries and the new developments on pyro-, hydro-, and bio-metallurgical routes have been revised. The manuscript describes the importance and benefits of recycling as regards the supply of critical metals and future trends towards a circular economy.

Asunto(s)

Automóviles , Suministros de Energía Eléctrica , Electricidad , Litio , Reciclaje

RESUMEN

Spent Li-ion batteries (LIBs) despite being produced with valuable metals from non-renewable natural resources are considered hazardous solid wastes because they contain metals and organic solvents pollutants for the environment. Due to this, it becomes necessary to know the chemical composition of these spent batteries to assist in the proper disposal and/or recycling process. This study aimed to provide quantitative data regarding the chemical composition of the cathode active material (CAM) of eight different spent LIBs used in cell phones and propose relationship with their energy capacity, year of manufacture and brand. CAM powder was leached using an environmentally friendly process with citric acid (2.0 mol L-1) and H2O2 (0.25 mol L-1), and the metals concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP OES). Co (43-67 wt%), Li (5.3-6.8 wt%), Mn (0.8-8.2 wt%), Ni (0.1-11.7 wt%) and Al (0.06-3.2 wt%) were present in higher concentrations, whereas Cr (0.0005-0.002 wt%), Cu (0.01-0.05 wt%), Mg (0.005-0.02 wt%), Ti (0.001-0.07 wt%), Ga (0.0009-0.03 wt%) and Zn (0.009-0.05 wt%) were present in lower concentrations. The result obtained showed a considerable variation between CAM elemental composition, which may be related to type of electrolyte, energy capacity and year of manufacture. Since this difference in chemical composition is not shown on product labels, this work using a green leaching process and a suitable analytical method may assist in the recycling processes and avoid the inappropriate disposal of the material.