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Aqueous zinc‐ion batteries have garnered renewed interest owing to their inherent safety and cost‐effectiveness. However, Zn anode suffers from notorious side reactions and dendrite growth, compromising the battery performance. Designing anion‐containing solvation structures to facilitate the in situ formation of a solid electrolyte interphase (SEI) layer proves effective in protecting Zn anode, yet balancing the inherent interactions between the cations‐solvents and cations–anions remains a significant challenge. Herein, latent solvent (hexafluoroisopropanol) with specific anion‐philic and cation‐phobic properties is introduced, which can remarkably increase Zn(TFSI)2 solubility in water and induce anion‐containing solvation structures. The introduction of latent solvent enables anions to preferentially decompose, giving rise to an anion‐derived SEI layer. More interestingly, the direct anion‐cation interaction endows Zn2+ species with stepwise dehydration, minimizing the adsorption of water on Zn anode. The anion‐derived SEI layer and optimized de‐solvation process work in synergy to enable homogeneous Zn deposition and ensure high reversibility. When coupled with a NaV3O8·1.5H2O (NVO) cathode, the resultant full cell delivers a high‐capacity retention of 87.8% after 2000 cycles at 1 A g−1. This work provides valuable insights into the advanced latent solvent electrolyte design and beyond. [ABSTRACT FROM AUTHOR]

The synthesis of in situ polymer-functionalized anatase TiO2 particles using an anchoring block copolymer with hydroxamate as coordinating species is reported, which yields nanoparticles (≈11 nm) in multigram scale. Thermal annealing converts the polymer brushes into a uniform and homogeneous carbon coating as proven by high resolution transmission electron microscopy and Raman spectroscopy. The strong impact of particle size as well as carbon coating on the electrochemical performance of anatase TiO2 is demonstrated. Downsizing the particles leads to higher reversible uptake/release of sodium cations per formula unit TiO2 (e.g., 0.72 eq. Na+ (11 nm) vs only 0.56 eq. Na+ (40 nm)) while the carbon coating improves rate performance. The combination of small particle size and homogeneous carbon coating allows for the excellent electrochemical performance of anatase TiO2 at high (134 mAh g−1 at 10 C (3.35 A g−1)) and low (≈227 mAh g−1 at 0.1 C) current rates, high cycling stability (full capacity retention between 2nd and 300th cycle at 1 C) and improved coulombic efficiency (≈99.8%). [ABSTRACT FROM AUTHOR]

Silicon‐based compounds are interesting candidate anode materials but show only relatively low electrochemical performances with sodium. Controversial reports are available about the electrochemical interaction between Na and silicon, which encourage to investigate the mechanism in a silicon‐based material in detail. This study reports the results of a systematic investigation of the electrochemical sodium ion storage in silicon oxycarbide (SiCO) using ex situ X‐ray photoelectron spectroscopy and magic‐angle spinning nuclear magnetic resonance spectroscopy. Comparison of pristine and hydrofluoric acid‐etched silicon oxycarbide shows that the silicon oxycarbide is active itself, but not by an alloying process. Instead, results reveal an irreversible structural change and amorphization of SiCO upon the initial sodium uptake and support the existence of reversible insertion‐based reactions in the subsequent cycles. A systematic investigation of the electrochemical sodium ion storage in silicon oxycarbide (SiCO) is reported. In this mechanistic study, reversible redox activity of Si during an insertion process is proved; furthermore, the existence of an alloying reaction between sodium and silicon or a reversible conversion reaction to form silicon carbide (SiC) is excluded. [ABSTRACT FROM AUTHOR]

The implementation of aqueous electrode processing of cathode materials is a key for the development of greener Na-ion batteries. Herein, the development and optimization of the aqueous electrode processing for the ecofriendly Na 0.44 MnO 2 (NMO) cathode material, employing carboxymethyl cellulose (CMC) as binder, are reported for the first time. The characterization of such an electrode reveals that the performances are strongly affected by the employed electrolyte solution, especially, the sodium salt and the use of electrolyte's additives. In particular, the best results are obtained using the 1 M solution of NaPF 6 in EC/DEC (ethylene carbonate/diethyl carbonate) 3:7 (v/v) + 2 wt % FEC (fluoroethylene carbonate). With this electrolyte, the outstanding capacity of 99.7 mA h g -1 is delivered by the CMC-NMO cathode after 800 cycles at a 1C charge/discharge rate. On the basis of this excellent long-term performance, a full sodium cell, composed of a CMC-based NMO cathode and hard carbon from biowaste (corn cob), has been assembled and tested. The cell delivers excellent performances in terms of specific capacity, capacity retention, and long-term cycling stability. After 75 cycles at a C/5 rate, the capacity of the NMO in the full-cell approaches 109 mA h g -1 with a Coulombic efficiency of 99.9%.

The synthesis of in situ polymer-functionalized anatase TiO 2 particles using an anchoring block copolymer with hydroxamate as coordinating species is reported, which yields nanoparticles (≈11 nm) in multigram scale. Thermal annealing converts the polymer brushes into a uniform and homogeneous carbon coating as proven by high resolution transmission electron microscopy and Raman spectroscopy. The strong impact of particle size as well as carbon coating on the electrochemical performance of anatase TiO 2 is demonstrated. Downsizing the particles leads to higher reversible uptake/release of sodium cations per formula unit TiO 2 (e.g., 0.72 eq. Na + (11 nm) vs only 0.56 eq. Na + (40 nm)) while the carbon coating improves rate performance. The combination of small particle size and homogeneous carbon coating allows for the excellent electrochemical performance of anatase TiO 2 at high (134 mAh g -1 at 10 C (3.35 A g -1 )) and low (≈227 mAh g -1 at 0.1 C) current rates, high cycling stability (full capacity retention between 2nd and 300th cycle at 1 C) and improved coulombic efficiency (≈99.8%).