Montse Casas-Cabanas

Alkali manganese oxynitridophosphates A1.1Mn2.9P3O8N2 (A = Na, Li) were prepared by one-step solid-state ammonolysis, where the lithium analogue is obtained directly rather than by alkali-ion exchange from the sodium compound. Both compositions crystallize in a previously unreported orthorhombic Pbcn framework, in which ordered O/N environments, unusual manganese coordination in MnO5N and MnO6N2 polyhedra, and alkali–manganese disorder are accommodated within the same structure. The proposed structural model is supported by complementary synchrotron X-ray and neutron powder diffraction, electron microscopy, solid-state NMR and XAS data, as well as density functional theory calculations. Magnetic susceptibility is consistent with predominantly Mn2+ and antiferromagnetic ordering below 35.1 K for the Li phase and 32.6 K for the Na phase. Although the Mn2+/Mn3+ redox couple lies within the accessible potential window of nonaqueous M-ion batteries, reversible alkali extraction is limited by the restricted migration pathways imposed by the framework. Overall, this work expands the compositional and structural landscape of oxynitridophosphates and highlights nitrogen incorporation in phosphate crystal chemistry as a route to unconventional coordination environments, new framework connectivities and functional properties.

In this work, we report a simple and efficient dehydration strategy to convert a double-layered δ-Na0.35V2O5·0.8H2O phase into a tunnel-structured β-NaxV2O5 (x ∼ 0.35) phase, enabling precise control over morphology, crystallinity, and surface chemistry. The structural evolution is tracked by temperature-resolved powder diffractometry, Raman spectroscopy, and Rietveld refinements, while electron microscopy reveals temperature-dependent morphology changes from lamellar to rod-like and prismatic shapes. Electrochemical testing demonstrates that the β phase obtained at 450 °C delivers the most favorable overall electrochemical performance, providing the optimal compromise between high-rate performance and long-term cycling stability, which is attributed to its isotropic particle morphology and favorable lithium diffusion pathways. In contrast, the sample obtained at 550 °C exhibits superior high-rate performance, albeit at the expense of accelerated degradation associated with mechanical stress accumulation and intraparticle cracking in the elongated prismatic particles. First-principles calculations identify the most energetically favorable sodium arrangements and their influence on lithium diffusion via a complex mechanism involving coupled ion dynamics. Overall, these results reveal how thermally directed topotactic transformations can be leveraged to optimize microstructure and redox behavior in tunnel-type vanadium bronzes, advancing their application as high-performance cathode materials for rechargeable batteries.

The electrochemical behavior of graphite anodes is strongly affected by structural disorder, yet graphite crystallinity is often described using averaged descriptors that do not resolve the underlying defect landscape. Here, we investigate a series of industrially relevant graphite samples combining high‑resolution synchrotron x‑ray diffraction with FAULTS‐based analysis of planar defects and operando measurements. We show that graphites with similar average crystallographic signatures span distinct defect‑topology regimes defined by different combinations of stacking faults, rhombohedral (3R) intergrowths and turbostratic interlayers. Operando diffraction reveals that lithium insertion does not initiate within an ideal 2H host, but proceeds preferentially through stacking‑faulted and 3R‑related environments, which provide structurally accessible insertion pathways. In contrast, turbostratic interlayers do not participate in early lithium insertion and correlate with reduced reversible capacity. These results demonstrate that graphite behavior is governed by defect topology rather than by a single degree of disorder and highlight the need for defect‑resolved structural descriptors to rationalize lithium intercalation mechanisms in graphite.

While Lithium-ion batteries dominate the current market, their widespread large-scale application can be limited by concerns regarding sustainability, cost and supply risk. This perspective evaluates emerging post-Li-ion chemistries, categorized by electrolyte type: aqueous, organic liquid, and solid-state, defining the concepts and describing the state-of-the art, with special emphasis in near-term manufacturable options. Aqueous electrolytes offer inherent non-flammability and high ionic conductivity but are fundamentally limited by the narrow thermodynamic stability window of water. Research in this area focuses on zinc-metal anodes, which face challenges related to dendritic growth and corrosion, and aqueous M-ion (Li ⁺ , Na ⁺ ) systems, which suffer from electrode active material degradation and limited operation voltages. Organic liquid electrolytes enable wider electrochemical windows. Sodium-ion batteries (SIBs) have emerged as credible ‘drop-in’ alternative, and though differences in Na ⁺ solvation and (solid electrolyte interphase) stability remain critical factors, market-ready cells are being developed and progressively entering early commercial applications. Potassium-ion batteries (KIBs) offer potential but are still in a very early stage of development. Technologies utilizing multivalent charge carriers (Mg ²⁺ , Ca ²⁺ , Al ³⁺ ) using metal anodes hold promise of high energy densities, yet practical developments are also limited. Room-temperature Solid-state batteries could bring in safety and energy density, but bottlenecks remain related to the chemical and mechanical instability of solid–solid interfaces. Overall, post-Li-ion battery research is characterized by a broad and dynamic landscape of technologies with very different maturity levels. Ongoing advances are progressively defining realistic application spaces while also revealing new roadblocks in the development. Rather than converging on a single successor, future energy storage is likely to rely on a diversified portfolio of complementary technologies tailored to specific applications whose viability will ultimately depend on a number of factors. A comparative technology assessment with minimum validation criteria and a critical roadmap that distinguishes near-term complementary technologies from conditional, niche and exploratory concepts is provided.

The electrochemical behaviour of graphite anodes is strongly affected by structural disorder, yet graphite crystallinity is often described using averaged descriptors that do not resolve the underlying defect landscape. Here, we investigate a series of industrially relevant graphite samples combining high‑resolution synchrotron X‑ray diffraction with FAULTS‑based analysis of planar defects and operando measurements. We show that graphites with similar average crystallographic signatures span distinct defect‑topology regimes defined by different combinations of stacking faults, rhombohedral (3R) intergrowths and turbostratic interlayers. Operando diffraction reveals that lithium insertion does not initiate within an ideal 2H host, but proceeds preferentially through stacking‑faulted and 3R‑related environments, which provide structurally accessible insertion pathways. In contrast, turbostratic interlayers do not participate in early lithium insertion and correlate with reduced reversible capacity. These results demonstrate that graphite behaviour is governed by defect topology rather than by a single degree of disorder and highlight the need for defect‑resolved structural descriptors to rationalize lithium intercalation mechanisms in graphite.

High‐voltage cathodes such as LiMn _1.5 Ni _0.5 O ₄ (LNMO) offer promising energy density but suffer from interfacial degradation accelerated at elevated voltages and temperatures. Here, we present a comprehensive comparative study of three Li ₃ PO ₄ coating methods (precipitation, sol–gel, and dry sol–gel routes) applied to commercial LNMO powders. Coating quality and intimacy are systematically assessed using a correlative, multitechnique approach including ⁷ Li and ³¹ P solid‐state NMR, X‐ray diffraction, and electrochemical testing. A key insight from this study is the use of ssNMR relaxation behavior as a sensitive probe of coating intimacy to the active phase. The methodology is validated on commercial LNMO and reproduced in a lab‐synthesized LNMO to demonstrate reproducibility across particle morphologies. Among all methods, the sol–gel route produced a uniform ∼20 nm coating with optimal surface contact, translating to improved rate capability and outstanding high‐temperature cycling stability (87% retention after 100 cycles at 50 °C compared to 29% for the non‐coated LNMO), while retaining rate capability. These findings establish a practical framework for designing robust interfacial coatings in high‐voltage lithium‐ion battery materials.

Low coulombic efficiency in the first redox cycle for lithium-rich oxides (LRO) can be successfully mitigated through blending with delithiated LiFePO ₄ .

Li⁺ and Na⁺ local ion dynamics in nitridophosphates Na₃V(PO₃)₃N and Li₃V(PO₃)₃N are evaluated here by means of solid-state nuclear magnetic resonance (NMR) and density functional theory (DFT) methods. In particular, the presence of diffusion pathways for the alkali metals within the crystal structures is evaluated experimentally by solid-state NMR and compared with bond valence energy landscape (BVEL) calculations. While no exchange between Na⁺ ions in Na₃V(PO₃)₃N was detected in the millisecond time scale, Li₃V(PO₃)₃N shows fast exchange between all Li⁺ positions in the structure. 2D ⁷Li-⁷Li EXSY solid-state NMR experiments performed at different mixing times were implemented to determine the Li-exchange rates. The observed diffusion mechanism involves the interconnection of all three alkali positions in the structure in a Li1 ↔ Li3 ↔ Li2 pattern. Nevertheless, the spontaneous Li exchange at room temperature between positions Li1 ↔ Li3 (k₁₃ = 826 Hz) is considerably faster than that between positions Li3 ↔ Li2 (k₂₃ = 207 Hz). These results are in agreement with the activation energies obtained for Li₃V(PO₃)₃N by the BVEL calculations performed in this work. These findings correlate well with the observed differences in the electrochemical performance of nitridophosphates A₃V(PO₃)₃N (A = Li, Na) and might be used to design future strategies for next-generation cathode materials.

Battery innovation relies on developing new electroactive materials. Addressing the growing need for energy storage solutions, the European Battery 2030+ Initiative targets accelerating by 5-to-10 fold the current rate of battery materials discovery within the next years¹. Taking up this challenge requires disruptive approaches that allow rethinking the traditional experimentation process, which is inherently slow and economically expensive. Indeed, the crystal-chemical landscape provided by the periodic table for discovering new battery materials is vast and remains far from being exhaustively explored. To expedite the investigation of extensive chemical spaces, considerable efforts have been made by exploring new theoretical approaches, however, only a few groups implemented high-throughput (HT) experimentation for battery research. Recent works have focused on limited types of material synthesis, electrolyte formulation, and cell assembly while the electrode processing that presents greater challenges due to its long preparation steps is still scarce and limited to specific multicell designs. For the last few years, CICenergiGUNE has been developing MAITENA, a Materials Acceleration and Innovation plaTform for ENergy Applications to accelerate the exploration rate of new materials for Li-ion and Na-ion battery materials in a cheaper and more reproducible way. In this presentation, we will present our strategy to screen inorganic materials for battery application, which includes the development of: automated screenings of materials databases in search for new electroactive materials², cost-effective modules to automatize a large variety of inorganic synthesis routes and an innovative electrode preparation method³ automated data treatment and analysis tools, including the new FullProfAPP that enables automated Rietveld refinements of large series of data⁴. References: Roadmap - Battery 2030+ Katcho NA, Carrete J, Reynaud M, Rousse G, Casas-Cabanas M, Mingo N, et al. Journal of Applied Crystallography. 2019;52(1):148-57. Ismail M, Cabañero MA, Orive J, Babulal LM, García J, Morant-Miñana MC, et al. ADEL: Automated Drop-cast Electrode Setup for High-throughput Screening of Battery Materials. Digital Discovery. Peer-Review. Arcelus O, Rodríguez-Carvajal J, Katcho NA, Reynaud M, Black AP, Chatzogiannakis D, et al. FullProfAPP: a graphical user interface for the streamlined automation of powder diffraction data analysis. 2024;57(5). Figure 1