New Insights into the Compositional Dependence of Li-Ion Transport in Polymer–Ceramic Composite Electrolytes

Composite electrolytes are widely studied for their potential in realizing improved ionic conductivity and electrochemical stability. Understanding the complex mechanisms of ion transport within composites is critical for effectively designing high-performance solid electrolytes. This study examines the compositional dependence of the three determining factors for ionic conductivity, including ion mobility, ion transport pathways, and active ion concentration. The results show that with increase in the fraction of ceramic Li₇La₃Zr₂O₁₂ (LLZO) phase in the LLZO–poly­(ethylene oxide) composites, ion mobility decreases, ion transport pathways transit from polymer to ceramic routes, and the active ion concentration increases. These changes in ion mobility, transport pathways, and concentration collectively explain the observed trend of ionic conductivity in composite electrolytes. Liquid additives alter ion transport pathways and increase ion mobility, thus enhancing ionic conductivity significantly. It is also found that a higher content of LLZO leads to improved electrochemical stability of composite electrolytes. This study provides insight into the recurring observations of compositional dependence of ionic conductivity in current composite electrolytes and pinpoints the intrinsic limitations of composite electrolytes in achieving fast ion conduction

Contents of 15 constituents in 7 decoctions.

<p>Contents of 15 constituents in 7 decoctions.</p

LC-MS/MS method validation for 15 constituents from BZ.

<p>LC-MS/MS method validation for 15 constituents from BZ.</p

Plasma concentration-time curves for psoralen, isopsoralen, psoralidin, xanthotoxin, and bergapten in SD rats after single oral administration of BZ.

<p>Plasma concentration-time curves for psoralen, isopsoralen, psoralidin, xanthotoxin, and bergapten in SD rats after single oral administration of BZ.</p

The drug–herb interaction network (D–H network) for BZ.

<p>BS, <i>P. corylifolia</i> and <i>C. monnieri</i>; BW, <i>P. corylifolia</i> and <i>A. carmichaelii</i>; BWS, <i>P. corylifolia</i>, <i>C. monnieri</i> and <i>A. carmichaelii</i>.</p

The chemical structures of 15 constituents in BZ.

<p>The chemical structures of 15 constituents in BZ.</p

Pharmacokinetic parameters of 5 constituents after single oral administration of BZ in SD rats.

<p>Pharmacokinetic parameters of 5 constituents after single oral administration of BZ in SD rats.</p

The drug–target association network (D–T network) for BZ.

<p>Green, the five compounds from BZ; Pink, the target-associated genes; Yellow, the shared genes among the five compounds.</p

Composite Polymer Electrolytes with Li₇La₃Zr₂O₁₂ Garnet-Type Nanowires as Ceramic Fillers: Mechanism of Conductivity Enhancement and Role of Doping and Morphology

Composite polymer solid electrolytes (CPEs) containing ceramic fillers embedded inside a polymer-salt matrix show great improvements in Li⁺ ionic conductivity compared to the polymer electrolyte alone. Lithium lanthanum zirconate (Li₇La₃Zr₂O₁₂, LLZO) with a garnet-type crystal structure is a promising solid Li⁺ conductor. We show that by incorporating only 5 wt % of the ceramic filler comprising undoped, cubic-phase LLZO nanowires prepared by electrospinning, the room temperature ionic conductivity of a polyacrylonitrile-LiClO₄-based composite is increased 3 orders of magnitude to 1.31 × 10^–4 S/cm. Al-doped and Ta-doped LLZO nanowires are also synthesized and utilized as fillers, but the conductivity enhancement is similar as for the undoped LLZO nanowires. Solid-state nuclear magnetic resonance (NMR) studies show that LLZO NWs partially modify the PAN polymer matrix and create preferential pathways for Li⁺ conduction through the modified polymer regions. CPEs with LLZO nanoparticles and Al₂O₃ nanowire fillers are also studied to elucidate the role of filler type (active vs passive), LLZO composition (undoped vs doped), and morphology (nanowire vs nanoparticle) on the CPE conductivity. It is demonstrated that both intrinsic Li⁺ conductivity and nanowire morphology are needed for optimal performance when using 5 wt % of the ceramic filler in the CPE

One-Pot Synthesis of Redox-Labile Polymer Capsules via Emulsion Droplet-Mediated Precipitation Polymerization

Monodisperse poly­(vinylcaprolactam) (PVCL)-based capsules are prepared by precipitation polymerization of vinylcaprolactam (VCL) onto dimethyldiethoxysilane (DMDES) emulsion droplets and removal of the DMDES templates by ethanol. Polymer chains in the shells can be cross-linked during the polymerization by disulfide-containing cross-linker <i>N</i>,<i>N</i>′-bis­(acryloyl) cystamine, which endows the capsules with an excellent redox-labile property. Versatility of this technique to prepare capsules with diverse components is demonstrated by the copolymerization of methacrylic acid (MAA) and VCL in the shell to prepare poly­(vinylcaprolactam-<i>co</i>-methacrylic acid) (P­(VCL-<i>co</i>-MAA)) capsules. The disulfide-bonded capsules can degrade efficiently into low molecular weight species (ca. 1200 Da) when the capsules are incubated with 10 mM glutathione (GSH) as the reducing agent. Delivery of the anticancer drug (doxorubicin, DOX) was also investigated in the P­(VCL-<i>co</i>-MAA) capsules. The cumulative <i>in vitro</i> release of DOX-loaded capsules allows a relatively low DOX release at pH 7.4. However, a burst release (ca. 90% in 6 h) of DOX was observed in the presence of 10 mM GSH. Cell viability assays show that the P­(VCL-<i>co</i>-MAA) capsules have negligible cytotoxicity to HeLa cancer cells. In comparison, DOX-loaded P­(VCL-<i>co</i>-MAA) capsules cause significant cell death following internalization. The reported capsules represent a novel and versatile class of stimuli-responsive carriers for controlled drug delivery