@article{21896,
  abstract     = {Redox-mediated flow batteries boost energy density by utilizing dissolved redox species as charge carriers for solid charge-storage materials. This strategy strongly depends on the thermodynamics and kinetics between the solid booster and dissolved redox species. Conventional electrochemical methods often convolute intrinsic reactivity with mass transport effects, introducing complexity in determining limiting steps. We propose a strategy that confines solid boosters within recessed microelectrodes and employs scanning electrochemical microscopy (SECM) to estimate reaction kinetics between booster and dissolved active redox species. Confining the solid booster in the recessed microelectrode overcomes mass transport limitations of dissolved redox species and enables controlled polarization of the booster material, allowing deconvolution of key rate-determining factors. As an initial model system, Prussian blue-ferricyanide/ferrocyanide [Fe(CN)6]3−/4− was used as solid booster and dissolved redox active species, respectively. The methodology was further explored for copper hexacyanoferrate with N,N,N-2,2,6,6-heptamethylpiperidinyl oxy-4-ammonium chloride and nickel hydroxide with [Fe(CN)6]3−/4− and extended to Mn-based Prussian blue analogues in combination with organic redox species. Our results demonstrate that SECM coupled with the proposed recessed microelectrode strategy provides a powerful platform to disentangle interfacial kinetics and guide the rational design of solid booster-dissolved redox species and electrolytes for high-performance redox-mediated flow batteries.},
  author       = {Santana Santos, Carla and Jiyane, Nomnotho and Quast, Thomas and Ibáñez, Maria and Rubio‐Presa, Rubén and Peljo, Pekka and Schuhmann, Wolfgang},
  issn         = {2566-6223},
  journal      = {Batteries & Supercaps},
  number       = {5},
  publisher    = {Wiley},
  title        = {{Evaluating reaction kinetics between solid booster and dissolved active species in redox‐mediated flow batteries using scanning electrochemical microscopy}},
  doi          = {10.1002/batt.70303},
  volume       = {9},
  year         = {2026},
}

@article{18881,
  abstract     = {The determination of the intrinsic properties of solid active material candidates is essential for their performance optimization. However, macroscopic electrodes and related analytical techniques show challenges concerning the number of additional influencing parameters. We explore recessed microelectrodes (rME) as a platform that allows for a binder-free investigation of Prussian Blue analogues (PBA), a family of promising battery materials. The enhanced diffusion using microelectrochemical tools is indispensable to assess the intrinsic material performance, overcoming the limitation of cation diffusion from the electrolyte to the solid interface during (dis)charging cycles and allowing the investigation of limiting steps in the coupled ion-electron transfer process. The intrinsic electrochemical performance of PBAs was studied in a three-electrode configuration by means of cyclic voltammetry and galvanostatic (dis)charging in aqueous Na+-containing electrolyte. We extended the evaluation to the role of the electrolyte on the performance of cathodic and anodic processes of a Mn-based PBA. Ex-situ and operando chemical characterization were coupled to support the microelectrochemical results.},
  author       = {Jiyane, Nomnotho and Santana Santos, Carla and Echevarria Poza, Igor and Palacios Corella, Mario and Abdillah Mahbub, Muhammad Adib and Marin-Tajadura, Gimena and Quast, Thomas and Ibáñez, Maria and Ventosa, Edgar and Schuhmann, Wolfgang},
  issn         = {2566-6223},
  journal      = {Batteries & Supercaps},
  number       = {3},
  publisher    = {Wiley},
  title        = {{Recessed microelectrodes as a platform to investigate the intrinsic redox process of Prussian blue analogs for energy storage application}},
  doi          = {10.1002/batt.202400743},
  volume       = {8},
  year         = {2025},
}

@misc{20042,
  abstract     = {The Cover Feature shows how recessed microelectrodes were employed as a versatile binder-free platform to investigate the electrochemical performance of Prussian Blue analogues (PBA), a class of promising battery materials, concerning capacity in varying aqueous electrolytes. To corroborate the micro-electrochemical findings, both ex-situ and operando chemical characterizations were conducted, offering complementary insights into the structural and chemical evolution of the PBA material during electrochemical cycling. More information can be found in the Research Article by W. Schuhmann and co-workers (DOI: 10.1002/batt.202400743).},
  author       = {Jiyane, Nomnotho and Santana Santos, Carla and Echevarria Poza, Igor and Palacios Corella, Mario and Abdillah Mahbub, Muhammad Adib and Marin‐Tajadura, Gimena and Quast, Thomas and Ibáñez, Maria and Ventosa, Edgar and Schuhmann, Wolfgang},
  booktitle    = {Batteries & Supercaps},
  issn         = {2566-6223},
  number       = {3},
  publisher    = {Wiley},
  title        = {{Cover Feature: Recessed microelectrodes as a platform to investigate the intrinsic redox process of Prussian blue analogs for energy storage application}},
  doi          = {10.1002/batt.202580302},
  volume       = {8},
  year         = {2025},
}