Vittorio Marangon

The concept of an electrolyte-flow system is applied for the first time to a Mg–air aqueous battery. The new cell achieves continuous discharge for up to 24 hours and a cumulative discharge time exceeding 90 hours via maintenance-assisted operation.

A novel fluorine-free single-ion-conducting polymer electrolyte allows for the stable cycling of Li∥LiFePO ₄ cells for more than 500 cycles.

Alternative configuration of lithium cell exploits electrode and polymer electrolyte cast all‐in‐one to form a membrane electrode assembly (MEA), in analogy to fuel cell technology. The electrolyte is based on polyethylene oxide (PEO), lithium bis‐trifluoromethane sulfonyl imide (LiTFSI) conducting salt, LiNO₃ sacrificial film‐forming agent to stabilize the lithium metal, and fumed silica (SiO₂) to increase the polymer amorphous degree. The membrane has conductivity ranging from ~5×10⁻⁴ S cm⁻¹ at 90 °C to 1×10⁻⁴ S cm⁻¹ at 50 °C, lithium transference number of ~0.4, and relevant interphase stability. The MEA including LiFePO₄ (LFP) cathode is cycled in polymer lithium cells operating at 3.4 V and 70 °C, with specific capacity of ~155 mAh g⁻¹ (1 C=170 mA g_LFP⁻¹) for over 100 cycles, without signs of decay or dendrite formation. The cell exploiting the MEA shows enhanced electrochemical performance as compared with the one using simple polymeric membrane stacked between cathode and anode. Furthermore, the MEA reveals the key advantage of possible scalability and applicability in roll‐to‐roll systems for achieving high‐energy lithium metal battery, as demonstrated by pouch‐cell application. These data may trigger new interest on this challenging battery exploiting the polymer configuration for achieving environmentally/economically sustainable, and safe energy storage.

TEMPO-oxidized cellulose nanofiber gel electrolyte is used in an attractive rechargeable Zn-ion battery delivering at 1.5 V a capacity exceeding 100 mA h g ⁻¹ , which is proposed for sustainable energy storage.

A Li‐ion battery combines a cathode benefitting from Sn and MnO₂ with high sulfur content, and a lithiated anode including fumed silica, few layer graphene (FLG) and amorphous carbon. This battery is considered a scalable version of the system based on lithium‐sulfur (Li−S) conversion, since it exploits at the anode the Li‐ion electrochemistry instead of Li‐metal stripping/deposition. Sn and MnO₂ are used as cathode additives to improve the electrochemical process, increase sulfur utilization, while mitigating the polysulfides loss typical of Li−S devices. The cathode demonstrates in half‐cell a maximum capacity of ~1170 mAh g_S⁻¹, rate performance extended over 1 C, and retention of 250 cycles. The anode undergoes Li‐(de)alloying with silicon, Li‐(de)insertion into amorphous carbon, and Li‐(de)intercalation through FLG, with capacity of 500 mAh g⁻¹ in half‐cell, completely retained over 400 cycles. The full‐cells are assembled by combining a sulfur cathode with active material loading up to 3 mg cm⁻² and lithiated version of the anode, achieved either using an electrochemical pathway or a chemical one. The cells deliver at C/5 initial capacity higher than 1000 mAh g_S⁻¹, retained for over ~40 % upon 400 cycles. The battery is considered a promising energy storage system for possible scaling‐up in pouch or cylindrical cells.

Glyme‐based electrolytes for sodium‐sulfur (Na–S) batteries are proposed for advanced cell configuration. Solutions of NaClO₄ or NaCF₃SO₃ in tetraglyme are investigated in terms of thermal stability, ionic conductivity, Na⁺‐transference number, electrochemical stability, stripping‐deposition ability, and chemical stability in Na‐cells. Subsequently, versions of the electrolytes doped with fluoroethylene carbonate (FEC) are prepared using 0.5, 1, 2, or 3% additive weight concentrations, and evaluated by adopting the same approach used for the bare solutions. Scanning electron microscopy (SEM) provides morphological details of the passivation layer formed on the Na electrodes, while X‐ray photoelectron spectroscopy (XPS) sheds light on its composition. The most relevant achievement of the FEC‐added electrolyte is the suppression of the polysulfide shuttle in Na–S cells using a cathode with 70 wt.% of sulfur in the composite. This result appears even more notable considering the low amount of the additive requested for enabling the reversible cell operation. The solutions using 1% of FEC show the best compromise between cell performance and stability. Cyclic voltammetry (CV) displays the potential region related to the FEC electrochemical process responsible for Na–S cell operation. The understanding of the electrolyte features enables additional cycling tests using sulfur cathode with an optimized current collector, increased specific capacity, and coulombic efficiency.