Comprehensive study of secondary zinc-air batteries: from material development to full cell validation

270 p.Las baterías secundarias de zinc-aire cuyo bajo coste y elevada densidad de energía despiertan un gran interés científico e industrial, han sido objetivo de desarrollo ya que su comercialización supondría una repercusión socioeconómica muy positiva.El trabajo realizado se enfocó en el análisis de cada uno de los componentes que conforman la tecnología, partiendo desde el nivel más elemental, como lo son los materiales activos que contienen los electrodos, hasta la obtención de un sistema completo de buenas propiedades electroquímicas y que podría ser utilizado como punto de partida para futuras investigaciones. Todo ello sin olvidar que el sistema electrolítico acuoso alcalino se ha definido como protagonista principal en las validaciones realizadas, debido a su efecto sobre las propiedades del resto de componentes de la celda y por tanto, sobre las prestaciones finales del sistema.IK4, CIDETE

Comprehensive study of secondary zinc-air batteries: from material development to full cell validation

270 p.Las baterías secundarias de zinc-aire cuyo bajo coste y elevada densidad de energía despiertan un gran interés científico e industrial, han sido objetivo de desarrollo ya que su comercialización supondría una repercusión socioeconómica muy positiva.El trabajo realizado se enfocó en el análisis de cada uno de los componentes que conforman la tecnología, partiendo desde el nivel más elemental, como lo son los materiales activos que contienen los electrodos, hasta la obtención de un sistema completo de buenas propiedades electroquímicas y que podría ser utilizado como punto de partida para futuras investigaciones. Todo ello sin olvidar que el sistema electrolítico acuoso alcalino se ha definido como protagonista principal en las validaciones realizadas, debido a su efecto sobre las propiedades del resto de componentes de la celda y por tanto, sobre las prestaciones finales del sistema.IK4, CIDETE

High performance carbon free bifunctional air electrode for advanced zinc-air batteries

Secondary zinc-air batteries (ZABs) offer a promising alternative for the future of sustainable energy storage. However, the current capability of secondary ZABs is far from satisfactory. The limitations for achieving high reversibility are mainly related to the bifunctional air electrodes as it severely hampers practical applications and commercialization of secondary ZABs. Many efforts have been devoted to the development of efficient and corrosion resistant bifunctional electrocatalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In ZABs, carbon is commonly used as conductive additive, however, it has been observed that carbon materials are not resistant to the high positive voltages applied in electrical recharge. In this work, the use of metallic nickel as alternative conductive additive in bifunctional air electrodes is explored and compared with carbon nanotubes (CNT). We demonstrate that the chemical resistance of CNT does not limit the electrode performance; but the density of the additive as well as its interaction with the active material is crucial for achieving long cycle life. The use of Ni as conductive agent in secondary ZABs boosted the cycle life by delivering more than 2,400 cycles, in contrast to the 88 cycles delivered by the analogous carbon-based battery.This work was supported by CDTI (ALMAGRID of the “CERVERA Centros Tecnológicos” program, CER-20191006), the Basque Country Government (CIC energiGUNE’20 of the ELKARTEK program, N° Exp. KK-2020/0078), the European Commission through the project ZABCAT “A New Zn-Air Battery Prototype to Overcome Cathode Degradation Through Catalyst Confinement” (grant agreement 966743) and the Ministerio de Ciencia e Innovación through the project AVANZA “Advanced Zn-Air Battery Prototype for the Energy Transition Horizon” (TED2021-131451B-C22). N. Ortiz-Vitoriano thanks Ramon y Cajal grant (RYC-2020-030104-I) funded by MCIN/AEI/10.13039/501100011033 and by FSE invest in your future

Towards Rechargeable Zinc-Air Batteries with Aqueous Chloride Electrolytes

This paper presents a combined theoretical and experimental investigation of aqueous near-neutral electrolytes based on chloride salts for rechargeable zinc-air batteries (ZABs). The resilience of near-neutral chloride electrolytes in air could extend ZAB lifetime, but theory-based simulations predict that such electrolytes are vulnerable to other challenges including pH instability and the unwanted precipitation of mixed zinc hydroxide chloride products. In this work, we combine theory-based simulations with experimental methods such as full cell cycling, operando pH measurements, ex-situ XRD, SEM, and EDS characterization to investigate the performance of ZABs with aqueous chloride electrolytes. The experimental characterization of near-neutral ZAB cells observes the predicted pH instability and confirms the composition of the final discharge products. Steps to promote greater pH stability and control the precipitation of discharge products are proposed.Comment: 13 pages, 12 figure

Reduction of Grain Boundary Resistance of La0.5Li0.5TiO3 by the Addition of Organic Polymers

The organic solvents that are widely used as electrolytes in lithium ion batteries present safety challenges due to their volatile and flammable nature. The replacement of liquid organic electrolytes by non-volatile and intrinsically safe ceramic solid electrolytes is an effective approach to address the safety issue. However, the high total resistance (bulk and grain boundary) of such compounds, especially at low temperatures, makes those solid electrolyte systems unpractical for many applications where high power and low temperature performance are required. The addition of small quantities of a polymer is an efficient and low cost approach to reduce the grain boundary resistance of inorganic solid electrolytes. Therefore, in this work, we study the ionic conductivity of different composites based on non-sintered lithium lanthanum titanium oxide (La0.5Li0.5TiO3) as inorganic ceramic material and organic polymers with different characteristics, added in low percentage (<15 wt.%). The proposed cheap composite solid electrolytes double the ionic conductivity of the less cost-effective sintered La0.5Li0.5TiO3.We thank the Spanish Ministry for Science and Technology (MAT2007-64486-C07-05) and CDTI (ALMAGRID of the "CERVERA Centros Tecnológicos" program, CER-20191006) for financial their support. JS, AV, SG, and FG also want to acknowledge Agencia Española de Investigación /Fondo Europeo de Desarrollo Regional (FEDER/UE) for funding the projects PID2019-106662RB-C41, C42, C43, and C44

Designing Aqueous Organic Electrolytes for Zinc-Air Batteries: Method, Simulation, and Validation

Aqueous zinc-air batteries (ZABs) are a low-cost, safe, and sustainable technology for stationary energy storage. ZABs with pH-buffered near-neutral electrolytes have the potential for longer lifetime compared to traditional alkaline ZABs due to the slower absorption of carbonates at non-alkaline pH values. However, existing near-neutral electrolytes often contain halide salts, which are corrosive and threaten the precipitation of ZnO as the dominant discharge product. This paper presents a method for designing halide-free aqueous ZAB electrolytes using thermodynamic descriptors to computationally screen components. The dynamic performance of a ZAB with one possible halide-free aqueous electrolyte based on organic salts is simulated using an advanced method of continuum modeling, and the results are validated by experiments. XRD, SEM, and EDS measurements of Zn electrodes show that ZnO is the dominant discharge product, and operando pH measurements confirm the stability of the electrolyte pH during cell cycling. Long-term full cell cycling tests are performed, and RRDE measurements elucidate the mechanism of ORR and OER. Our analysis shows that aqueous electrolytes containing organic salts could be a promising field of research for zinc-based batteries, due to their Zn$^{2+}$ chelating and pH buffering properties. We discuss the remaining challenges including the electrochemical stability of the electrolyte components.Comment: 16 pages, 12 figure

Manganese oxide catalysts for secondary zinc air batteries: from

An efficient, durable and low cost air cathode with low polarization between the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential for a high performance and durable secondary zinc-air battery. Different valence states and morphologies of MnxOy catalysts were synthetized via thermal treatment of EMD (generating Mn2O3 and Mn3O4) and acid digestion of synthetized Mn2O3 (producing a-MnO2) in order to develop an efficient Bifunctional Air Electrode (BAE). Change in the ratio H+ to Mn2O3 during the acid digestion affects the sample microporosity, the crystallographic plane distribution, as well as the physical and chemical adsorbed water which was related to defects, i.e. cation vacancies (Mn4+) and Mn3+. These characteristics were discussed and linked to the electrocatalytic activity. The best ORR performing catalyst was that with the higher surface water content (associated to material BET surface area) and a (310) surface as the 2nd more contributing plane (after 211). On the other hand, the catalyst with the higher structural water and with (110) and (200) crystallographic planes being the most intensity contributors (after 211) was the most OER active material. In this work, it was able to find a relationship between catalyst structure and air-efficiency through a volcano-like relationship between air-efficiency and surface water content. Air-efficiency (also take as round-efficiency discharge/charge in battery context) can be taken as a good descriptor of potentially good materials for Zn-Air secondary batteries technology. In this term, we were able to prepare a Bifunctional Air Electrode based on the selected a-MnO2 sample which demonstrated a roundefficiency of 53%, a DV around 1 V and a neglected loss of the charge potential (about 2.1 V) over the entire lifecycle test (more 200 cycles over 30 hours) with a capacity retention superior to 95%.European Commission H2020: Proyecto ZAS “Zinc Air Secondary innovative nanotech based batteries for efficient energy storage” (Grant Agreement 646186

A practical perspective on the potential of rechargeable Mg batteries

Emerging energy storage systems based on abundant and cost-effective materials are key to overcome the global energy and climate crisis of the 21st century. Rechargeable Magnesium Batteries (RMB), based on Earth-abundant magnesium, can provide a cheap and environmentally responsible alternative to the benchmark Li-ion technology, especially for large energy storage applications. Currently, RMB technology is the subject of intense research efforts at laboratory scale. However, these emerging approaches must be placed in a real-world perspective to ensure that they satisfy key technological requirements. In an attempt to bridge the gap between laboratory advancements and industrial development demands, herein, we report the first non-aqueous multilayer RMB pouch cell prototypes and propose a roadmap for a new advanced RMB chemistry. Through this work, we aim to show the great unrealized potential of RMBs.This work was funded by European Union's Horizon 2020 research and innovation program under the FET Proactive call with grant agreement no 824066 via the “E-MAGIC” project

A practical perspective on the potential of rechargeable Mg batteries

Emerging energy storage systems based on abundant and cost-effective materials are key to overcome the global energy and climate crisis of the 21st century. Rechargeable Magnesium Batteries (RMB), based on Earth-abundant magnesium, can provide a cheap and environmentally responsible alternative to the benchmark Li-ion technology, especially for large energy storage applications. Currently, RMB technology is the subject of intense research efforts at laboratory scale. However, these emerging approaches must be placed in a real-world perspective to ensure that they satisfy key technological requirements. In an attempt to bridge the gap between laboratory advancements and industrial development demands, herein, we report the first non-aqueous multilayer RMB pouch cell prototypes and propose a roadmap for a new advanced RMB chemistry. Through this work, we aim to show the great unrealized potential of RMBs

Comprehensive study of secondary zinc-air batteries: from material development to full cell validation

270 p.Las baterías secundarias de zinc-aire cuyo bajo coste y elevada densidad de energía despiertan un gran interés científico e industrial, han sido objetivo de desarrollo ya que su comercialización supondría una repercusión socioeconómica muy positiva.El trabajo realizado se enfocó en el análisis de cada uno de los componentes que conforman la tecnología, partiendo desde el nivel más elemental, como lo son los materiales activos que contienen los electrodos, hasta la obtención de un sistema completo de buenas propiedades electroquímicas y que podría ser utilizado como punto de partida para futuras investigaciones. Todo ello sin olvidar que el sistema electrolítico acuoso alcalino se ha definido como protagonista principal en las validaciones realizadas, debido a su efecto sobre las propiedades del resto de componentes de la celda y por tanto, sobre las prestaciones finales del sistema.IK4, CIDETE