Organic batteries based on just redox polymers

[EN]Redox-active polymers have gained interest as environmentally friendly alternative to inorganic materials in applications such as electrodes in lithium-ion batteries. All-polymer batteries were first disregarded with respect to other technologies due to their lower energy densities. However, the inherent benefits of redox polymers such as processability, flexibility, recyclability, high-rate performance and the perspective to prepare batteries from renewable resources has re-ignited interest in recent years. This review article aims to provide a comprehensive overview on the state of the art of batteries in which the active material is a redox polymer; including "static" all-polymer batteries and polymer-air batteries but also "flowing" systems such as polymer based redox-flow batteries (pRFB). First, a succinct overview of the recent developments of redox polymers will be given, summarizing the historic trends and developments. Second, an exhaustive discussion of the various battery prototypes will be provided, considering all steps in the development of organic batteries just based in redox polymers. Finally, future perspectives on all-polymer batteries will be discussed, summarizing the major challenges that are still to be overcome to unlock their commercial implementation.Authors thank POLYSTORAGE ETN project, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No 860403. RM and NP thank the Spanish MCI through the SUSBAT project (Ref. RTI2018-101049-B-I0 0) and Juan de la Cierva fellowship [FJC2018-037781-I] (MCI-AEI/FEDER, UE) . NC would like to thank the University of the Basque Country forfunding through a specialization of research staff fellowship (ES-PDOC 19/99) . NG acknowledges the funding from the European Union's Horizon 2020 framework programme under the Marie Skodowska-Curie Agreement No. 101028682

Single-ion conducting poly(ethylene oxide carbonate) as solid polymer electrolyte for lithium batteries

Unformatted postprintSingle-ion conducting polymer electrolytes (SIPE) have attracted a lot of interest for application in high energy density lithium metal batteries. SIPEs possess lithium transport numbers close to unity, which does not provoke concentration gradients and holds the promise of limiting lithium dendrite formation. In this article, we have optimized a single-ion polymer incorporating the most successful chemical units in polymer electrolytes, such as ethylene oxide, carbonate and a lithium sulfonimide. This single-ion poly(ethylene oxide carbonate) copolymer was synthesized by polycondensation between polyethylene glycol, dimethyl carbonate and a functional diol including the pendant sulfonamide anionic group and the lithium counter-cation. By playing with the monomer stoichiometry, the crystallinity and ionic conductivity were optimized. The best copolymer showed high ionic conductivity values of 1.2·10-4 S.cm-1 at 70 °C. Lithium interactions and mobility were studied by lithium pulsed field gradient, lithium diffusion, NMR relaxation time measurements and FTIR-ATR analysis. High lithium mobility is observed which is due to the weakly coordinating chemical environment in the polymer and also that the sulfonamide in the SIPE adopts to a greater extent the cis conformation, which is known to promote lithium mobility. Finally, the performance of the singe-ion conducting poly(ethylene oxide carbonate) was compared in lithium symmetric cells versus an analogous conventional salt in polymer electrolyte, showing improved performance in lithium plating and stripping.We are grateful to the financial support of the European Research Council by the Starting Grant Innovative Polymers for Energy Storage (iPes) 306250 and IONBIKE (H2020-MSCA-RISE-2018-823989), and by the Basque Government through ETORTEK Energigune 2013 and IT 999-16. Leire Meabe thanks Spanish Ministry of Education, Culture and Sport for the predoctoral FPU fellowship received to carry out this work. The authors thank for the technical and human support provided by SGIker of UPV/EHU for the NMR facilities of Gipuzkoa campus. The authors thank also Dr. Jose Ignacio Miranda (SGIker) for useful and essential support. Authors would like to thank the human support of Dr. Haijin Zhu and Dr. Luke O’Dell

From Plastic Waste to New Materials for Energy Storage

The use of plastic waste to develop high added value materials, also known as upcycling, is a useful strategy towards the development of more sustainable materials. More specifically, the use of plastic waste as a feedstock for synthesising new materials for energy storage devices can not only provide a route to upgrading plastic waste but can also help in the search for sustainable materials. This perspective describes recent strategies for the use of plastic waste as a sustainable, cheap and abundant feedstock in the production of new materials for electrochemical energy storage devices such as lithium batteries, sodium batteries and supercapacitors. Two main strategies are described, the development of conducting carbons by combustion of plastic waste and the depolymerization of plastics into new chemicals and materials. In both cases, catalysis has been key to ensuring high efficiency and performance. Future opportunities and challenges are highlighted and hypotheses are made on how the use of plastic waste could enhance the circularity of current energy storage devices.NG acknowledges the funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028682. CJ acknowledges the financial support from el Ministerio de ciencia e innovación from the Juan de la Cierva Program (FJC2020-045872-I). The funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028975 and Ministerio de ciencia e innovación under PDC2021-121461-I00 project is acknowledged

Chemical Upcycling of PET Waste towards Terephthalate Redox Nanoparticles for Energy Storage

Over 30 million ton of poly(ethylene terephthalate) (PET) is produced each year and no more than 60% of all PET bottles are reclaimed for recycling due to material property deteriorations during the mechanical recycling process. Herein, a sustainable approach is proposed to produce redox-active nanoparticles via the chemical upcycling of poly(ethylene terephthalate) (PET) waste for application in energy storage. Redox-active nanoparticles of sizes lower than 100 nm were prepared by emulsion polymerization of a methacrylic-terephthalate monomer obtained by a simple methacrylate functionalization of the depolymerization product of PET (i.e., bis-hydroxy(2-ethyl) terephthalate, BHET). The initial cyclic voltammetry results of the depolymerization product of PET used as a model compound show a reversible redox process, when using a 0.1 M tetrabutylammonium hexafluorophosphate/dimethyl sulfoxide electrolyte system, with a standard redox potential of −2.12 V vs. Fc/Fc+. Finally, the cycling performance of terephthalate nanoparticles was investigated using a 0.1 M TBAPF6 solution in acetonitrile as electrolyte in a three-electrode cell. The terephthalate anode electrode displays good cycling stability and performance at high C-rate (i.e., ≥5C), delivering a stable specific discharge capacity of 32.8 mAh.g−1 at a C-rate of 30 C, with a capacity retention of 94% after 100 cycles. However, a large hysteresis between the specific discharge and charge capacities and capacity fading are observed at lower C-rate (i.e., ≤2C), suggesting some irreversibility of redox reactions associated with the terephthalate moiety, in particular related to the oxidation process.NC would like to thank the University of the Basque Country for funding through a specialization of research staff fellowship (ESPDOC 19/99). JD thanks WBI International and the Gobierno Vasco/Eusko Jaurlaritza (IT 999–16) for fundings. NG acknowledges the funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028682

Aging Effect of Catechol Redox Polymer Nanoparticles for Hybrid Supercapacitors

[EN] Redox-polymer nanoparticles are a promising solution to avoid the detrimental dissolution of organic electrode materials while showing discrete redox processes. In this work, catechol-based redox-active polymer nanoparticles (cRPNs) were synthesized through one-step emulsion polymerization with a tunable size from 25 to 150 nm. The fresh cRPNs were characterized and showed a reversible redox process centered at 0.50 V (vs. Ag/AgCl) in 1 M H2SO4. Unexpectedly, the cRPN latex aged after days passing from white to pink. This aging resulted in a shift of its redox potential toward higher values, which could be associated to autoxidation of the catechol groups and subsequent crosslinking of NPs due to catechol dimer formation. Finally, we compared the performance of fresh and aged cRPNs in a hybrid supercapacitor device, proving how the aging effect had some benefits such as an increase in the voltage output, specific capacitance, cyclability and Coulombic efficiencies of the device.The authors thank for technical and human support provided by IZO-SGI SGIker of UPV/EHU. Technical and human support provided by IZO-SGI, SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) is gratefully acknowledged for assistance and generous allocation of computational resources. The authors would like to thank the European Commission for financial support through funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 823989. N.P. appreciates Spanish MINECO for the Juan de la Cierva-formation fellowship (FJC2018-037781-I). R.M. thanks the Spanish Ministry of Science, Innovation and Universities through the SUSBAT project (Ref.RTI2018-101049-B-I00) (MINECO/FEDER, UE) for financial support

Dual redox-active porous polyimides as high performance and versatile electrode material for next-generation batteries

Energy storage will be a primordial actor of the ecological transition initiated in the energy and transport sectors. As such, innovative approaches to design high-performance electrode materials are crucial for the development of the next generation of batteries. Herein, a novel dual redox-active and porous polyimide network (MTA-MPT), based on mellitic trianhydride (MTA) and 3,7-diamino-N-methylphenothiazine (MPT) monomers, is proposed for applications in both high energy density lithium batteries and symmetric all-organic batteries. The MTA-MPT porous polyimide was synthesized using a novel environmentally-friendly hydrothermal polymerization method. Rooted in its dual redox proprieties, the MTA-MPT porous polyimide exhibits a high theoretical capacity making it a very attractive cathode material for high energy density battery applications. The cycling performance of this novel electrode material was assessed in both high energy density lithium batteries and light-weight symmetric all-organic batteries, displaying excellent rate capability and long-term cycling stability.N. Goujon acknowledges the funding from the European Union's Horizon 2020 framework programme under the Marie Sklodowska-Curie agreement No. 101028682. M. Lahnsteiner, H. M. Moura, D. A. Cerron-Infantes and M. M. Unterlass acknowledge funding through the Austrian Science Fund's (FWF) START programme under grant no. Y1037-N28. We thank Dr Jerpme Roeser and Prof. Arne Thomas (TU Berlin) for gas sorption measurements

Single-Ion Conducting Polymer Nanoparticles as Functional Fillers for Solid Electrolytes in Lithium Metal Batteries

[EN]Composite solid electrolytes including inorganic nanoparticles or nanofibers which improve the performance of polymer electrolytes due to their superior mechanical, ionic conductivity, or lithium transference number are actively being researched for applications in lithium metal batteries. However, inorganic nanoparticles present limitations such as tedious surface functionalization and agglomeration issues and poor homogeneity at high concentrations in polymer matrixes. In this work, we report on polymer nanoparticles with a lithium sulfonamide surface functionality (LiPNP) for application as electrolytes in lithium metal batteries. The particles are prepared by semibatch emulsion polymerization, an easily up-scalable technique. LiPNPs are used to prepare two different families of particle-reinforced solid electrolytes. When mixed with poly(ethylene oxide) and lithium bis(trifluoromethane)sulfonimide (LiTFSI/PEO), the particles invoke a significant stiffening effect (E' > 106 Pa vs 105 Pa at 80 °C) while the membranes retain high ionic conductivity (sigma = 6.6 * 10-4 S cm-1). Preliminary testing in LiFePO4 lithium metal cells showed promising performance of the PEO nanocomposite electrolytes. By mixing the particles with propylene carbonate without any additional salt, we obtain true single-ion conducting gel electrolytes, as the lithium sulfonamide surface functionalities are the only sources of lithium ions in the system. The gel electrolytes are mechanically robust (up to G' = 106 Pa) and show ionic conductivity up to 10-4 S cm-1. Finally, the PC nanocomposite electrolytes were tested in symmetrical lithium cells. Our findings suggest that all-polymer nanoparticles could represent a new building block material for solid-state lithium metal battery applications.L.P. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska–Curie grant agreement no. 797295. P.S. has been funded by the SNSF (Swiss National Science Foundation) under project number P2FRP2_191846. J.R.L. and D.M. acknowledge the funding by the Basque Government (IT99-16). V.B. acknowledges support from the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract no. DE-AC05-00OR22725. A.S. acknowledges financial support for dielectric measurements and data discussions by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division

Polyimides as Promising Cathodes for Metal-Organic Batteries: A Comparison between Divalent (Ca2+, Mg2+) and Monovalent (Li+, Na+) Cations

Ca- and Mg-based batteries represent a more sustainable alternative to Li-ion batteries. However, multivalent cation technologies suffer from poor cation mass transport. In addition, the development of positive electrodes enabling reversible charge storage currently represents one of the major challenges. Organic positive electrodes, in addition to being the most sustainable and potentially low-cost candidates, compared with their inorganic counterparts, currently present the best electrochemical performances in Ca and Mg cells. Unfortunately, organic positive electrodes suffer from relatively low capacity retention upon cycling, the origin of which is not yet fully understood. Here, 1,4,5,8-naphthalenetetracarboxylic dianhydride-derived polyimide was tested in Li, Na, Mg, and Ca cells for the sake of comparison in terms of redox potential, gravimetric capacities, capacity retention, and rate capability. The redox mechanisms were also investigated by means of operando IR experiments, and a parameter affecting most figures of merit has been identified: the presence of contact ion-pairs in the electrolyte.Funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 715087) is gratefully acknowledged. ICMAB-CSIC members are grateful for funding through PTI+ TRANSENER+: “Alta Tecnología clave en la transición en el ciclo energético”, part of the CSIC program for the Spanish Recovery, Transformation and Resilience Plan funded by the Recovery and Resilience Facility of the European Union, established by the Regulation (EU) 2020/2094 and thank the Spanish Agencia Estatal de Investigación Severo Ochoa Programme for Centres of Excellence in R&D (CEX2019-000917-S).With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe