Polydopamine was utilized an adhesive interface for the uniform coating of Au nanoparticles in the pores of polydimethylsiloxane to enhance the output performance of triboelectric nanogenerators.

For the development of all-solid-state lithium metal batteries (LMBs), a highporous silica aerogel (SA)-reinforced single-Li + conducting nanocomposite polymer electrolyte (NPE) is prepared via two-step selective functionalization. The mesoporous SA is introduced as a mechanical framework for NPE as well as a channel for fast lithium cation migration. Two types of monomers containing weak-binding imide anions and Li + cations are synthesized and used to prepare NPEs, where these monomers are grafted in SA to produce SAbased NPEs (SANPEs) as ionomer-in-framework. This hybrid SANPE exhibits high ionic conductivities (≈10 −3 S cm −1 ), high modulus (≈10 5 Pa), high lithium transference number (0.84), and wide electrochemical window (>4.8 V). The resultant SANPE in the lithium symmetric cell possesses long-term cyclic stability without short-circuiting over 800 h under 0.2 mA cm −2 . Furthermore, the LiFePO 4 |SANPE|Li solid-state batteries present a high discharge capacity of 167 mAh g −1 at 0.1 C, good rate capability up to 1 C, wide operating temperatures (from −10 to 40 °C), and a stable cycling performance with 97% capacity retention and 100% coulombic efficiency after 75 cycles at 1 C and 25 °C. The SANPE demonstrates a new design principle for solid-state electrolytes, allowing for a perfect complex between inorganic silica and organic polymer, for high-energy-density LMBs.

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Solid-state aqueous polymer electrolytes (SAPEs), a mixture of hydrophilic polymers and an appropriate amount of water, can produce high Li-ion conductivity while maintaining a solid state. Also, they can overcome the limitations of normal solid electrolytes. This study reports that the very high SAPE ionic conductivity (∼10 mS/cm at T = 298.15 K) originates from a low energy barrier (∼0.28 eV) closely correlated with water-filled ion passages in the medium. The low energy barrier is ascribed to a considerable reduction of the enthalpic barrier due to water addition despite a growth of the entropic barrier incurred by the negative nature of entropy change across water tubes. The extremely high ionic conductivity, coupled with an exceptionally low energy barrier, provides a unique advantage to SAPEs over conventional solid electrolytes.

The molecular level understanding of ion and polymer dynamics in nanoparticle-coupled hydrogel network polymer electrolytes is investigated by linear dielectric and viscoelastic measurements covering broad ranges of frequency and temperature. We prepare hydrogel polymer electrolytes (HPEs), composed of Li + conducting hydrophilic poly(lithium acrylate) (PLiA) as the HPE matrix and vinyl-functionalized silica nanoparticles (NPs) as cross-linking points, via radical polymerization and sol−gel reaction. The NP content variation leads to changes in ionic conductivity (σ DC ), dielectric constant (ε s ), relaxation frequency, and elastic modulus, which are important characteristic factors for understanding ion transport. From the physical model of electrode polarization (EP), allowing for the determination of the number density of simultaneously conducting ions and their mobility, the NP-containing HPEs (HPE-NP) have simultaneously higher conducting ion concentration (p) and mobility (μ), resulting in higher ionic conductivity (σ DC ∼ pμ), compared to the HPE without NPs. The temperature dependence of p and μ follows Arrhenius (thermally activated) and Vogel−Fulcher (segmentally driven) temperature dependences, respectively. In addition to the lower frequency EP, the HPEs show higher frequency relaxation (α 2 ), attributed to ions rearranging. NP incorporation leads to faster α 2 relaxation and higher static dielectric constant ε s (shorter Bjerrum length l B ). Time−temperature superposition (tTS) works well for these electrolytes and is applied to construct master curves of viscoelasticity and in-phase conductivity. In the end, the NP-containing HPE-based supercapacitor is fabricated using carbon nanotube yarn (CNTY) electrodes and shows stable electrochemical performance, demonstrating that our HPE can be a solid-state polymer electrolyte for energy storage devices.