Review—Innovative Polymeric Materials for Better RechargeableBatteries: Strategies from CIC Energigune

The need for sustainable energy sources and their efficient utilization has motivated extensive explorations of new electrolytes, electrodes, and alternative battery chemistries departing from current lithium-ion battery ( LIB) technologies. The evolution and development of rechargeable batteries are tightly linked to the research of polymeric materials, such as polymer electrolytes and redox-active polymeric electrodes, separators, and binders, etc. In this contribution, we review the recent progresses on polymer electrolytes and redox-active polymeric electrodes developed in CIC Energigune with particular attention paid to the molecular designing and engineering. On the basis of our knowledge and experience accumulated in rechargeable batteries, further developments and improvements on the properties of these polymeric materials for building better rechargeable batteries are discussed. (c) The Author(s) 2019. Published by ECS.This work was supported by GV-ELKARTEK-2016 from the Basque Government, and MINECO RETOS (Ref: ENE2015-64907-C2-1-R) from Spanish Government. H.Z. thanks the Basque Government for the Berrikertu program (1-AFW-2017-2). This manuscript is dedicated to the 73th birthday of Prof. Dr. Michel Armand, who ushered theoretical concepts leading to practical applications in energy-related electrochemistry

Structure, Composition, Transport Properties, and Electrochemical Performance of the Electrode‐Electrolyte Interphase in Non‐Aqueous Na‐Ion Batteries

Rechargeable Li-ion battery technology has progressed due to the development of a suitable combination of electroactive materials, binders, electrolytes, additives, and electrochemical cycling protocols that resulted in the formation of a stable electrode-electrolyte interphase. It is expected that Na-ion technology will attain a position comparable to Li-ion batteries dependent on advancements in establishing a stable electrode-electrolyte interphase. However, Li and Na are both alkali metals with similar characteristics, yet the physicochemical properties of these systems differ. For this reason, a detailed study on the electrode-electrolyte interphase properties, composition, and structure is required to understand the factors that influence the battery\u27s behavior. Herein, the research that has been performed on the electrode-electrolyte interphase for both anode and cathode in the most important families of electrode materials, including carbonate ester-based and advanced electrolytes such as ether-based carbonates and ionic liquids is presented

Influence of the Current Density on the Interfacial Reactivity of Layered Oxide Cathodes for Sodium‐Ion Batteries

The full commercialization of sodium-ion batteries (SIBs) is still hindered by their lower electrochemical performance and higher cost ($ W-1 h(-1)) with respect to lithium-ion batteries. Understanding the electrode-electrolyte interphase formation in both electrodes (anode and cathode) is crucial to increase the cell performance and, ultimately, reduce the cost. Herein, a step forward regarding the study of the cathode-electrolyte interphase (CEI) by means of X-ray photoelectron spectroscopy (XPS) has been carried out by correlating the formation of the CEI on the P2-Na0.67Mn0.8Ti0.2O2 layered oxide cathode with the cycling rate. The results reveal that the applied current density affects the concentration of the formed interphase species, as well as the thickness of CEI, but not its chemistry, indicating that the electrode-electrolyte interfacial reactivity is mainly driven by thermodynamic factors.The authors would like to thank B. Acebedo for her support with materials synthesis, characterization, and testing, and E. Gonzalo for the fruitful discussions. M.Z. thanks the Basque Government for her Post-doc fellowship (POS_2017_1_0006). HIU authors (M.Z and S.P.) acknowledge the Helmholtz Association Basic funding. Open Access Funding provided by Universita degli Studi di Camerino within the CRUI-CARE Agreement

Structure, Composition, Transport Properties, and Electrochemical Performance of the Electrode-Electrolyte Interphase in Non-Aqueous Na-Ion Batteries

[EN] Rechargeable Li-ion battery technology has progressed due to the development of a suitable combination of electroactive materials, binders, electrolytes, additives, and electrochemical cycling protocols that resulted in the formation of a stable electrode-electrolyte interphase. It is expected that Na-ion technology will attain a position comparable to Li-ion batteries dependent on advancements in establishing a stable electrode-electrolyte interphase. However, Li and Na are both alkali metals with similar characteristics, yet the physicochemical properties of these systems differ. For this reason, a detailed study on the electrode-electrolyte interphase properties, composition, and structure is required to understand the factors that influence the battery's behavior. Herein, the research that has been performed on the electrode-electrolyte interphase for both anode and cathode in the most important families of electrode materials, including carbonate ester-based and advanced electrolytes such as ether-based carbonates and ionic liquids is presented.Ministerio de Ciencia, Innovación y Universidades. Grant Number: PID2019- 107468RB-C21 Gobierno Vasco Eusko Jaurlaritza. Grant Number: IT1226-1

Influence of the Current Density on the Interfacial Reactivity of Layered Oxide Cathodes for Sodium-Ion Batteries

The full commercialization of sodium-ion batteries (SIBs) is still hindered by their lower electrochemical performance and higher cost ($ W-1 h(-1)) with respect to lithium-ion batteries. Understanding the electrode-electrolyte interphase formation in both electrodes (anode and cathode) is crucial to increase the cell performance and, ultimately, reduce the cost. Herein, a step forward regarding the study of the cathode-electrolyte interphase (CEI) by means of X-ray photoelectron spectroscopy (XPS) has been carried out by correlating the formation of the CEI on the P2-Na0.67Mn0.8Ti0.2O2 layered oxide cathode with the cycling rate. The results reveal that the applied current density affects the concentration of the formed interphase species, as well as the thickness of CEI, but not its chemistry, indicating that the electrode-electrolyte interfacial reactivity is mainly driven by thermodynamic factors.The authors would like to thank B. Acebedo for her support with materials synthesis, characterization, and testing, and E. Gonzalo for the fruitful discussions. M.Z. thanks the Basque Government for her Post-doc fellowship (POS_2017_1_0006). HIU authors (M.Z and S.P.) acknowledge the Helmholtz Association Basic funding. Open Access Funding provided by Universita degli Studi di Camerino within the CRUI-CARE Agreement

Influence of Using Metallic Na on the Interfacial and Transport Properties of Na-Ion Batteries

Na2Ti3O7 is a promising negative electrode for rechargeable Na-ion batteries; however, its good properties in terms of insertion voltage and specific capacity are hampered by the poor capacity retention reported in the past. The interfacial and ionic/electronic properties are key factors to understanding the electrochemical performance of Na2Ti3O7. Therefore, its study is of utmost importance. In addition, although rather unexplored, the use of metallic Na in half-cell studies is another important issue due to the fact that side-reactions will be induced when metallic Na is in contact with the electrolyte. Hence, in this work the interfacial and transport properties of full Na-ion cells have been investigated and compared with half-cells upon electrochemical cycling by means of X-ray photoelectron spectroscopy (conventional XPS and Auger parameter analysis) and electrochemical impedance spectroscopy. The half-cell has been assembled with C-coated Na2Ti3O7 against metallic Na whilst the full-cell uses C-coated Na2Ti3O7 as negative electrode and NaFePO4 as positive electrode, delivering 112 Wh/kganode+cathode in the 2nd cycle. When comparing both types of cells, it has been found that the interfacial properties, the OCV (open circuit voltage) and the electrode—electrolyte interphase behavior are more stable in the full-cell than in the half-cell. The electronic transition from insulator to conductor previously observed in a half-cell for Na2Ti3O7 has also been detected in the full-cell impedance analysis

Designing Perovskite Oxides for Solid Oxide Fuel Cells

Perovskite-type oxides with the general formula ABO3 have been widely studied and are utilized in a large range of applications due to their tremendous versatility. In particular, the high stability of the perovskite structure compared to other crystal arrangements and its ability, given the correct selection of A and B cations, to maintain a large oxygen vacancy concentration makes it a good candidate as electrode in solid oxide fuel cell (SOFC) applications. Utilizing this novel structure allows the engineering of advanced, effective electrolytes for such devices. This review details the development of current state-of-the-art perovskite-type oxides for solid oxide fuel cell (SOFC) applications

Structurally stable Mg-doped P2-Na2/3Mn1-yMgyO2 sodium-ion battery cathodes with high rate performance : insights from electrochemical, NMR and diffraction studies

This work was partially supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, under the Batteries for Advanced Transportation Technologies (BATT) Program subcontract #7057154 (R.J.C). C.P.G. and R.J.C. thank the EU ERC for an Advanced Fellowship for CPG. This work was partially supported by the LINABATT project from the Ministerio de Economía Competitividad under Contract No. ENE2013-44330-R (G.S. and T.R.). P.G.B. is grateful to the EPSRC, including the SUPREGEN programme, for financial support.Sodium-ion batteries are a more sustainable alternative to the existing lithium-ion technology and could alleviate some of the stress on the global lithium market as a result of the growing electric car and portable electronics industries. Fundamental research focused on understanding the structural and electronic processes occurring on electrochemical cycling is key to devising rechargeable batteries with improved performance. We present an in-depth investigation of the effect of Mg doping on the electrochemical performance and structural stability of Na2/3MnO2 with a P2 layer stacking by comparing three compositions: Na2/3Mn1-yMgyO2 (y = 0.0, 0.05, 0.1). We show that Mg substitution leads to smoother electrochemistry, with fewer distinct electrochemical processes, improved rate performance and better capacity retention. These observations are attributed to the more gradual structural changes upon charge and discharge, as observed with synchrotron, powder X-ray, and neutron diffraction. Mg doping reduces the number of Mn3+ Jahn-Teller centers and delays the high voltage phase transition occurring in P2-Na2/3MnO2. The local structure is investigated using 23Na solid-state nuclear magnetic resonance (ssNMR) spectroscopy. The ssNMR data provide direct evidence for fewer oxygen layer shearing events, leading to a stabilized P2 phase, and an enhanced Na-ion mobility up to 3.8 V vs. Na+/Na upon Mg doping. The 5% Mg-doped phase exhibits one of the best rate performances reported to date for sodium-ion cathodes with a P2 structure, with a reversible capacity of 106 mAhg-1 at the very high discharge rate of 5000 mAg-1. In addition, its structure is highly reversible and stable cycling is obtained between 1.5 and 4.0 V vs. Na+/Na, with a capacity of approximately 140 mAhg-1 retained after 50 cycles at a rate of 1000 mAg-1.Publisher PDFPeer reviewe