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The ongoing surge in demand for high-energy/flexible rechargeable batteries relentlessly drives technological innovations in cell architecture as well as electrochemically active materials. Here, a new class of all-nanomat lithium-ion batteries (LIBs) based on 1D building element-interweaved heteronanomat skeletons is demonstrated. Among various electrode materials, silicon (Si, for anode) and overlithiated layered oxide (OLO, for cathode) materials are chosen as model systems to explore feasibility of this new cell architecture and achieve unprecedented cell capacity. Nanomat electrodes, which are completely different from conventional slurry-cast electrodes, are fabricated through concurrent electrospinning (for polymeric nanofibers) and electrospraying (for electrode materials/carbon nanotubes (CNTs)). Si (or rambutan-shaped OLO/CNT composite) powders are compactly embedded in the spatially interweaved polymeric nanofiber/CNT heteromat skeletons that play a crucial role in constructing 3D-bicontinuous ion/electron transport pathways and allow for removal of metallic foil current collectors. The nanomat Si anodes and nanomat OLO cathodes are assembled with nanomat Al2O3 separators, leading to the fabrication of all-nanomat LIB full cells. Driven by the aforementioned structural/chemical uniqueness, the all-nanomat full cell shows exceptional improvement in electrochemical performance (notably, cell-based gravimetric energy density = 479 W h kgCell−1) and also mechanical deformability, which lie far beyond those achievable with conventional LIB technologies.

A composite separator membrane (CSM) with an A/B/A type layered structure, composed of a microporous electrolyte-philic poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) gel layer (A) and a submicrometer porous polyethylene (PE) or a macroporous poly(ethylene terephthalate) (PET) non-woven matrix (B), is introduced in a dye-sensitized solar cell (DSSC). Commercially available PE and PET separator membranes (SMs) act as matrices that provide mechanical stability to the DSSC and permanent pore structures for facilitated ion transport. PVdF-HFP is used as a microporous gelator for improved interfacial contact between the solid SM and the electrodes. The PVdF-HFP gel impedes the charge recombination process between electron and I3 − at the TiO2/electrolyte interface, resulting in improved electron lifetimes. The DSSC assembled with the CSM exhibits high initial solar energy conversion efficiency (η, 6.1%) and stable η values over 1400 h, demonstrating good long term stability. The behaviors of the DSSC are attributed to the synergistic factors of the CSM, such as improved ion conductivity, electrolyte affinity, electrolyte retention capability, effective interfacial contact, and plausible passivation of the dyes. This study demonstrates a practical combination of short- and long-term DSSC performance through the introduction of the CSM.

The combination of high-capacity anodes and high-voltage cathodes has garnered a great deal of attention in the pursuit of high-energy-density lithium-ion batteries. As a facile and scalable electrode-architecture strategy to achieve this goal, a direct one-pot decoration of high-capacity silicon (Si) anode materials and of high-voltage LiCoO2 (LCO) cathode materials is demonstrated with colloidal nanoparticles composed of electroconductive antimony-doped tin oxide (ATO). The unusual ATO nanoparticle shells enhance electronic conduction in the LCO and Si electrode materials and mitigate unwanted interfacial side reactions between the electrode materials and liquid electrolytes. The ATO-coated LCO materials (ATO-LCO) enable the construction of a high-mass-loading cathode and suppress the dissolution of cobalt and the generation of by-products during high-voltage cycling. In addition, the ATO-coated Si (ATO-Si) anodes exhibit highly stable capacity retention upon cycling. Integration of the high-voltage ATO-LCO cathode and high-capacity ATO-Si anode into a full cell configuration brings unprecedented improvements in the volumetric energy density and in the cycling performance compared to a commercialized cell system composed of LCO/graphite.