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The photopolymerization-induced microphase separation (photo-PIMS) process involving a reactive polymer block was implemented to fabricate nanostructured quasi-solid polymer electrolytes (QSPEs) for use in lithium metal batteries (LMBs). This innovative one-pot fabrication enhances interfacial properties in LMBs by enabling in situ nanostructuring of QSPE directly onto the electrodes. This process also allows for customization of QSPE structural dimensions by tweaking the architecture and molar mass of poly[(oligo ethylene glycol) methyl ether methacrylate- co -styrene] (P(OEGMA- co -S)) macromolecular chain transfer agent. Bicontinuous nanoscale domains of soft P(OEGMA- co -S)/propylene carbonate/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) phase and hard poly[isobornyl acrylate- co -(oligo ethylene glycol)diacrylate] phase furnished the QSPEs with respectively high ionic conductivity (0.34 mS cm -1 at 30 °C) and interesting level of mechanical strength (10 6 -10 7 Pa at 30 °C). The as-prepared QSPE showed decent electrochemical properties and an electrochemical stability window of about 4.2 V vs Li + /Li. This electrolyte enables the Li||SPE||Li symmetric cell to cycle over 350 h at 0.1 mA cm -2 without evidence of dendrite formation. By means of galvanostatic cycling studies on a prototype lithium metal battery with LiNi 0.8 Mn 0.1 Co 0.1 O 2 or LiFePO 4 positive electrodes, we further demonstrate that the in situ nanostructured QSPE exhibited better performances than the corresponding stacked battery.

Poly(2,2,6,6-tetramethyl-1-piperidinyloxy methacrylate) (PTMA) is one of the most promising organic cathode materials thanks to its relatively high redox potential, good rate performance, and cycling stability. However, being a p-type material, PTMA-based batteries pose additional challenges compared to conventional lithium-ion systems due to the involvement of anions in the redox process. This study presents a comprehensive approach to optimize such batteries, addressing challenges in electrode design, scalability, and cost. Experimental results at a laboratory scale demonstrate high active mass loadings of PTMA electrodes (up to 9.65 mg cm -2 ), achieving theoretical areal capacities that exceed 1 mAh cm -2 . Detailed physics-based simulations and cost and performance analysis clarify the critical role of the electrolyte and the impact of the anion amount in the PTMA redox process, highlighting the benefits and the drawbacks of using highly concentrated electrolytes. The cost and energy density of lithium metal batteries with such high mass loading PTMA cathodes were simulated, finding that their performance is inferior to batteries based on inorganic cathodes even in the most optimistic conditions. In general, this work emphasizes the importance of considering a broader perspective beyond the lab scale and highlights the challenges in upscaling to realistic battery configurations.

High-performance electrolytes are at the heart of magnesium battery development. Long-term stability along with the low potential difference between plating and stripping processes are needed to consider them for next-generation battery devices. Within this work, we perform an in-depth characterization of the novel Mg[Al(hfip) 4 ] 2 salt in different glyme-based electrolytes. Specific importance is given to the influence of water content and the role of additives in the electrolyte. Mg[Al(hfip) 4 ] 2 -based electrolytes exemplify high tolerance to water presence and the beneficial effect of additives under aggravated cycling conditions. Finally, electrolyte compatibility is tested with three different types of Mg cathodes, spanning different types of electrochemical mechanisms (Chevrel phase, organic cathode, sulfur). Benchmarking with an electrolyte containing a state-of-the-art Mg[B(hfip) 4 ] 2 salt exemplifies an improved performance of electrolytes comprising the Mg[Al(hfip) 4 ] 2 salt and establishes Mg[Al(hfip) 4 ] 2 as a new standard salt for the future Mg battery research.

Insights into the electrochemical processes occurring at the electrode-electrolyte interface are a crucial step in most electrochemistry domains and in particular in the optimization of the battery technology. However, studying potential-dependent processes at the interface is one of the biggest challenges, both for theoreticians and experimentalists. The challenge is pushed further when stable species also depend on the concentration of specific ligands in the electrolyte, such as chlorides. Herein, we present a general theoretical ab initio methodology to compute a Pourbaix-like diagram of complex electrolytes as a function of electrode potential and anion's chemical potential, that is, concentration. This approach is developed not only for the bulk properties of the electrolytes but also for electrode-electrolyte interfaces. In the case of chlorinated magnesium complexes in dimethoxyethane, we show that the stability domains of the different species are strongly shifted at the interface compared to the bulk of the electrolyte because of the strong local electric fields and charges occurring in the double layer. Thus, as the interfacial stability domains are strongly modified, this approach is necessary to investigate all interface properties that often govern the reaction kinetics, such as solvent degradation at the electrode. Interface Pourbaix diagram is used to give some insights into the improved stability at the Mg anode induced by the addition of chloride. Because of its far-reaching insights, transferability, and wide applicability, the methodology presented herein should serve as a valuable tool not only for the battery community but also for the wider electrochemical one.