The development of electrolytes displaying good transport properties, high thermal stability, low flammability, high safety is of crucial importance for the realization of advanced metal-ion batteries [1]. In this work we report about a series of novel electrolytes for lithium and sodium-based batteries, which have been developed with the aim to match above mentioned characteristics, together with a high sustainability and low price.

We will consider the use of electrolytes containing imide and borate based salts in combination with ƴ-valelolactone (GVL), which is bio-derived solvent already produced in large scale. We will show that these innovative electrolytes allow the realization of lithium-ion batteries and sodium-ion batteries displaying high performance and high cycling stability. Furthermore, we will report about an innovative aqueous-based recycling process which allows an effective recovering of the solvent and salt of these bio-based electrolytes [2,3]

The comprehensive understanding of interface formation and evolution remains one of the most important challenges for rapid battery innovation, as these interfaces play a pivotal role on both performance and safety[1]. The gas evolution signature of interfacial processes can be highly informative, and operando gas analysis techniques have become an essential tool for accelerating battery innovation[2-6]. Electrochemical mass spectrometry (EMS) can provide quantitative information of individual processes occurring in the cell, as well as their interconnectivity (e.g., cathode-anode crosstalk and anode slippage) with high sensitivity and resolution.

Here we present online electrochemical mass spectrometry (OEMS) studies of systems with both high-nickel cathode materials and high-voltage anode materials that show the nature, onset, extent and interconnectivity of parasitic reactions leading to cell aging using very short test protocols. Our results indicate the need for better understanding these processes in order to accurately target solutions such as electrolyte formulations, coatings, etc., to accelerate materials innovation in batteries.

The increasing use of lithium-ion batteries (LIBs) in portable devices and electric vehicles will result in a growth of spent LIBs. Disposing of these batteries wastes valuable critical mineral resources and has a significant environmental impact. Given that the materials of greatest economic value are found in the cathode, the development of efficient recycling strategies for the recovery of cathode materials from spent LIBs is essential[1]. Direct recycling methods, which restore the structure of degraded cathode particles without compromising the bulk phase, have emerged as an energy-efficient alternative to conventional metallurgical processes, whose multi-step nature requires substantial quantities of chemical agents[2]. Although direct recycling of cathode material has clear environmental and energy efficiency advantages, scaling limitations of reported methods have restricted large-scale implementation.

In this work, we describe a novel and scalable method for the direct electrochemical recycling of lithium iron phosphate (LFP) from discarded LiBs, using a flow cell and the redox mediation process. Electrochemical recycling using redox mediators effectively restores the oxidation state of iron and facilitates the reinsertion of Li ions, effectively addressing the main degradation mechanism of cathode LFP. In this procedure, pellets of degraded LFP powder (S-LFP) are placed in a tank, where they are directly reduced and relithiated by a redox mediator (RM_red) dissolved in an aqueous electrolyte containing lithium (relithiation anolyte), pumped from an electrochemical cell into the relithiation tank. Redox mediators transport charge from the electrochemical cell, where Li₄Fe(CN)₆ is oxidized, to the S-LFP pellets, while Li ions are supplied from a counter compartment containing Li₄Fe(CN)₆ through an ion-selective membrane. Consumption of the redox mediator regeneration solution is minimal thanks to a closed-loop electrochemical regeneration process. The concept is validated using two different redox mediators, each associated with different energy demands in the recycling process. The total regeneration of the S-LFP is confirmed by structural and electrochemical characterization, showing that the regenerated material has a crystalline structure comparable to that of the LFP in a new cathode.

In this lecture, I present our latest research on the development of digital tools to optimize battery manufacturing processes. I discuss our digital models based on physics-based numerical simulations, artificial intelligence, and hybrid approaches capable of predicting how manufacturing parameters impact the properties and performance of electrodes and cells.[1-4,7]

These models are coupled with multi-objective optimization algorithms to predict the manufacturing recipes required to reach specific property and performance targets. This inverse design concept paves the way toward digital twins for battery manufacturing.[1,4] 

I provide illustrations of application of our concept for lithium ion, sodium ion, solid state and redox flow batteries. 

Furthermore, I present our recent work on the interaction of the human operators with the digital models by leveraging Virtual Reality (VR) and Mixed Reality (MR). These immersive tools are also utilized to train students, as illustrated by examples from the Erasmus+ Master's programme i-MESC.[5,6]

Finally, I will discuss our recently created spin-off company dedicated to transferring our modeling and digital technology to the industrial sector.

The fabrication of electrodes through dry-processing represents the oportunity to develop a sustainable, low-cost next generation sodium ion batteries, enabling wide adoption of this novel technology. However, dry processing presents several challenges, particularly concerning the integration of binder materials and porosity for efficient electrolyte impregnation. While polytetrafluoroethylene (PTFE), a fluorine-rich fibrillating polymer, is traditionally used in dry-processed electrodes, is unsuitable for anodic lithium-ion materials due to its decomposition at low potentials, compromising electrode stability and capacity retention. [1] Additionally, fluorine-containing polymers are well-recognized for their health hazards and challenging recyclability, highlighting the need for safer and more sustainable options. [2]

In this study, both PTFE  and various fluorine-free polymers were tested to improve the mechanical and electrochemical performance of carbonaceous and layered oxide electrodes. Changes in materials’ particle size and the inclusion of foams were explored to optimize electrode structure and porosity. However, the primary challenge was insufficient porosity, which limited electrolyte penetration and overall performance. These results highlight the need for novel polymer materials and processing strategies to achieve the necessary porosity for improved performance and sustainability in dry-manufactured electrodes.

Scaling up solid-state batteries (SSBs) from controlled lab-scale demonstrations to commercially relevant pouch cells remains a major barrier to their widespread adoption, especially when inorganic solid electrolytes are used. [1,2] Although solid-state batteries offer substantial advantages, including enhanced safety, higher energy density, and compatibility with lithium-metal or silicon-rich anodes, the transition from well-controlled laboratory cells to larger, application-relevant formats introduces a series of complex processing challenges. These challenges include controlling large-batch electrolyte synthesis, ensuring consistent particle properties, and enabling scalable composite electrode fabrication.  At the cell level, achieving sufficient densification demands high uniaxial or isostatic pressure, but applying these pressures uniformly in larger formats increases the risk of mechanical stress, cracking of brittle sulfide materials, and interfacial contact loss. As cell size grows, maintaining homogeneous stack pressure and stable, low-resistance interfaces becomes increasingly difficult, and even minor voids or micro-cracks can raise impedance, hinder ionic transport, and reduce cycling stability, ultimately limiting manufacturability and performance. [3]

In this talk, I will present our recent progress in developing solid-state pouch cells based on the argyrodite-type electrolyte Li₆PS₅Cl, combined with LiNi₀.₈Mn₀.₁Co₀.₁O₂ and advanced silicon-based composite anodes. I will highlight how key processing parameters, such as particle size distribution, compaction and formation pressure, and interfacial engineering, affect the microstructural stability, ionic transport, and electrochemical performance of both individual components [4]  and the complete pouch cell.

Group 14 materials (C,Si,Ge,Sn) are the most studied family of anode materials for Li-ion batteries.¹ While graphite has been the cornerstone of Li-ion battery anode development, it has limited capacity (which limits energy density) and there is growing supply chain uncertainty. In contrast, Si,Ge,Sn are significantly higher capacity materials than graphite but require significant optimisation, as their Li alloying/dealloying mechanisms cause expansion/contraction that can lead to premature cell failure. Group 14 materials also have potential for Na-ion, Li metal and dual-cation systems, which can be built upon Li-ion efforts, to deliver high-performance 'beyond Li-ion' battery chemistries.² This talk will examine recent efforts in the development of Group 14 materials for Li-ion, Li-metal and Dual-cation batteries. The Li-ion component will focus on Si nanowire anode materials, from direct growth of nanowires on current collectors,³ to upscaling of Si/graphite composites to the kg scale. Understanding of the fundamental charge/discharge mechanisms and material evolution during cycling will be discussed alongside SEI control approaches. The challenges associated with upscaling and importance of full-cell testing will be detailed. The ability of Group 14 nanomaterials to guide Li metal stripping/plating as a route towards hosted Li metal anode will then be detailed, using Ge as a model systems.⁴ Finally, our recent investigations of dual-cation alloying (Li-Na) in Ge will be discussed,⁵ as a route towards higher energy densities, where Li cations in the electrolyte serve as a capacity booster. Overall, the talk will highlight the potential and remaining hurdles for the use of Group 14 materials in energy storage applications.

The design of next-generation battery electrodes increasingly relies on advanced additive-manufacturing techniques capable of tuning transport properties through precise architectural control. Among the most widely used additive-manufacturing approaches is Direct Ink Writing (DIW), which enables the fabrication of architected electrodes by extruding printable inks while maintaining low processing temperatures and material versatility [1].

In parallel, the semi-empirical master-curve model proposed by Tian et al. [2] has emerged as a predictive tool for describing the master curve (capacity vs. current relationship) in conventional planar electrodes, using electrode thickness as the sole geometric parameter. However, this model is intrinsically restricted to flat architectures and cannot capture the transport phenomena introduced by structured 3D geometries.

In this work, we fabricate 3D-structured LFP electrodes via DIW, implementing different vertical and periodic architectures, as well as planar electrodes of various thicknesses as references. Electrochemical measurements show that these structured electrodes exhibit a consistent enhancement in high-rate performance, directly demonstrating the key influence of geometry on ionic and electronic transport.

Motivated by the inability of the original model [2] to describe structured electrodes, we present a generalization of the master-curve model applicable to any electrode geometry. The extended formulation replaces the thickness-based descriptor with geometry-independent transport parameters obtained from a single cross-section image of the electrode: Ionic Medium Path (IMP), Electronic Medium Path (EMP), ionic interfacial area (Aᵢ), electronic interfacial area (Aₑ), and electrode volume (V).

By applying the model to our different experimental electrode geometries, we are able to determine which transport process is rate-limiting and identify the optimal geometry within our experimental limitations.

The increasing demand for efficient and sustainable energy storage systems, driven by the need to decouple energy production peaks from consumption and by the electrification of heavy transportation, has highlighted the potential of Zn-O₂ batteries. These batteries offer an energy density up to three times higher than that of conventional Li-ion batteries, making them a promising alternative to fossil fuels for air and waterborne transport applications.

Despite their advantages, Zn-O₂ batteries face significant challenges, including limited cyclability, component instability, the high cost of organic electrolytes, and dependence on bifunctional catalysts based on precious group metals or cobalt. Overcoming these limitations requires the development of efficient and sustainable bifunctional catalysts for both the oxygen reduction reaction and the oxygen evolution reaction.

This study focuses on the synthesis of Fe-based bifunctional catalysts using iron chlorides as precursors via a sol-gel method, incorporating surfactants and urea as a nitrogen source. Unlike previous studies in which Fe compounds were mainly investigated as complementary or secondary catalysts, this work evaluates their performance as standalone bifunctional catalysts.

The Fe-based catalysts were synthesized at low temperatures and supported on Ni foam. Structural characterization using FTIR and XRD confirmed successful nitrogen incorporation into their structure. Electrochemical testing demonstrated excellent long-term stability, with sustained charge and discharge cycling and no observable degradation or passivation over more than 4000 hours of operation. Furthermore, the catalysts exhibited high selectivity for both the oxygen reduction and oxygen evolution reactions, while offering reduced environmental impact and lower cost compared to commercial alternatives.

This work represents a significant step toward the development of cost-effective and environmentally friendly Zn–O₂ batteries, enhancing their potential for large-scale and real-world energy storage applications.

Silicon (Si) is a leading candidate for next-generation lithium-ion battery anodes due to its exceptionally high theoretical specific capacity (3,579 mAh g⁻¹). However, its practical implementation is hindered by the ~300% volume expansion during lithiation, which induces mechanical fracture, loss of electrical connectivity, and unstable solid-electrolyte interphase (SEI) growth. Because these processes occur simultaneously and interact, they obscure the fundamental mechanisms governing long-term performance, highlighting the need for simplified, reproducible model systems that allow individual degradation pathways to be isolated.

In this work, we employ a 100% silicon nanowire (SiNW) anode as a controlled platform to investigate degradation and transport limitations in silicon electrodes. SiNWs are synthesized via a solvent free floating catalyst CVD process that assembles them into freestanding macroscopic textiles with tunable loading, thickness, and porosity [1]. The resulting electrodes exhibit high structural uniformity, enabling reproducible electrochemical measurements and minimizing variability from fabrication.

Electron microscopy and spectroscopy show that the electrodes consist of crystalline ~20 nm nanowires forming a mechanically robust, highly interconnected network that operates without conductive carbon or polymeric binders [2]. These electrodes deliver reproducible capacities of ~2700 mAh g⁻¹ at C/20 and maintain areal capacities above 6 mAh cm⁻² in thicker configurations. Long-term cycling demonstrates that mechanical degradation (dominant in particle-based Si anodes) is not the limiting factor here: the network remains intact after hundreds of cycles, ruling out pulverization and electrical disconnection as primary causes of capacity fading [3].

Instead, a progressive increase in electrochemical polarization emerges as the dominant degradation mode. Differential capacity analysis, impedance spectroscopy, and image-based quantification show that polarization growth correlates with continuous SEI thickening, which increases interfacial resistance and reduces accessible porosity, as well as with the stability of the interface with the current collector. Adhesion-controlled experiments confirm that poor interfacial bonding accelerates resistance growth and voltage hysteresis.

Interpreting these results also requires acknowledging the limitations of lithium metal counter electrodes in half-cell studies. Morphological instability, electrolyte depletion, and uneven current distribution in Li metal can artificially amplify the apparent polarization of high-capacity anodes, complicating the separation of intrinsic degradation from counter-electrode artefacts.

Finally, the talk will argue that Si anodes are a central material for the electrification of transport in coming decades, and strategically important for Europe given its lack of battery critical raw materials. Si anodes could enable EV ranges close to 1000 km and charge times below 15 minutes, while reducing pressure on natural graphite by hundreds of kilotonnes per annum. This transition could avoid megatonne-scale CO₂ emissions from battery-material production, according to estimates.