Influence of Carbonate-Based Additives on the Electrochemical Performance of Si NW Anodes Cycled in an Ionic Liquid Electrolyte

Dual-Salt Low-Concentration Electrolyte for Low-Temperature Sodium Metal Batteries

The high theoretical capacity of 1165 mAh g-1 and lower cost position sodium metal batteries (SMBs) as a promising alternative to lithium-based batteries. However, their application at ultralow temperatures is limited by conventional commercial electrolytes, which present challenges such as an unstable solid electrolyte interphase (SEI) and suboptimal ionic kinetic performance. Building on the significant impact of low concentration and the pivotal role of SEI films in enhancing the cycle stability of batteries, we develop a low-concentration and dual-salt carbonate electrolyte. This low-concentration electrolyte enhances the fluidity of the electrolyte, while the dual-salt system promotes the formation of a high proportion of anions solvated structure and robust inorganic SEI films. This innovative combination markedly improves the ionic kinetic performance and low temperature cycle life. Consequently, the Na||Na symmetric cell with this electrolyte exhibits a prolonged cycling life of 900 h, while the Na||Na3V2(PO4)3 full cell maintains a capacity of 70.5 mAh g-1 over 100 cycles at -40 °C.

Morphological Evolution and Solid-Electrolyte Interphase Formation on LiNi0.6Mn0.2Co0.2O2 Cathodes Using Highly Concentrated Ionic Liquid Electrolytes

Employing high-voltage Ni-rich cathodes in Li metal batteries (LMBs) requires stabilization of the electrode/electrolyte interfaces at both electrodes. A stable solid-electrolyte interphase (SEI) and suppression of active material pulverization remain the greatest challenges to achieving efficient long-term cycling. Herein, studies of NMC622 (1 mAh cm^-2) cathodes were performed using highly concentrated N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide (C₃mpyrFSI) 50 mol % lithium bis(fluorosulfonyl)imide (LiFSI) ionic liquid electrolyte (ILE). The resulting SEI formed at the cathode enabled promising cycling performance (98.13% capacity retention after 100 cycles), and a low degree of ion mixing and lattice expansion was observed, even at an elevated temperature of 50 °C. Fitting of acquired impedance spectra indicated that the SEI resistivity (R_SEI) had a low and stable contribution to the internal resistivity of the system, whereas active material pulverization and secondary grain isolation significantly increased the charge transfer resistance (R_CT) throughout cycling.

Functionalized Activated Carbon for Competing Adsorption of Volatile Organic Compounds and Water

The interfacial interaction of activated carbon with volatile organic compounds (VOCs) is seriously affected by water vapor. Therefore, it is vital to enhance the hydrophobic performance of activated carbon for expanding its application in industrial and environmental fields. Herein, a series of hydrophobic activated carbon was fabricated by tailored mixed siloxane and applied in dynamic competitive adsorption at 0, 50, and 90% humidity. Simultaneously, the diffusion molecular models and multicomponent adsorption experiments were used to study the adsorption and diffusion mechanisms. The hydrophobicity of activated carbon was significantly improved by loading of mixed siloxane, in which the equilibrium water absorption decreased from 21.9 to 7.2% and the contact angles increased by 70.10°. Meanwhile, dynamic competitive adsorption at different humidities indicated that the siloxane-functionalized activated carbons (SACs) showed much better competitive adsorption performances for VOCs than original activated carbon, which was further confirmed by the theoretical calculations of adsorption energy. In addition, a remarkable adsorption selectivity and reusability could be demonstrated to VOCs with different polarities on SACs. This study not only provides a new strategy for the hydrophobic modification of activated carbon materials but also offers theoretical guidance for the treatment of gas streams with significant water contents.

Metal Phenolic Network-Integrated Multistage Nanosystem for Enhanced Drug Delivery to Solid Tumors

Metal-phenolic networks (MPNs) are an emerging class of supramolecular surface modifiers with potential use in various fields including drug delivery. Here, the development of a unique MPN-integrated core-satellite nanosystem (CS-NS) is reported. The "core" component of CS-NS comprises a liposome loaded with EDTA (a metal ion chelator) in the aqueous core and DiR (a near-infrared photothermal transducer) in the bilayer. The "satellite" component comprises mesoporous silica nanoparticles (MSNs) encapsulating doxorubicin and is coated with a Cu²⁺ -tannic acid MPN. Liposomes and MSNs self-assemble into the CS-NS through adhesion mediated by the MPN. When irradiated with an 808 nm laser, CS-NS liberated the entrapped EDTA, leading to Cu²⁺ chelation and subsequent disassembly of the core-satellite nanostructure. Photo-conversion from the large assembly to the small constituent particles proceeded within 5 min. Light-triggered CS-NS disassembly enhanced the carrier and cargo penetration and accumulation in tumor spheroids in vitro and in orthotopic murine mammary tumors in vivo. CS-NS is long circulating in the blood and conferred improved survival outcomes to tumor-bearing mice treated with light, compared to controls. These results demonstrate an MPN-integrated multistage nanosystem for improved solid tumor treatment.