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Electro-chemo-mechanical degradation pathways that significantly impact performance of ceramic battery electrodes are a strong function of bulk crystallographic texture, crystal size, and interfacial misorientation angle. Via electrodeposition, deterministic synthesis of textured thick (>10 μm) films of LiCoO2 having controlled size dispersity and interfaces is demonstrated, enabling study and control of these degradation pathways. The crystal morphogenesis stems from the growth parameters (current density and temperature), resulting in a bouquet of textures and microstructures. Columnar grained ⟨110⟩||ND textured films with a finer crystallite size (f4–8 μm = 0.617) can be synthesized in kinetic regimes of growth (T = 275 °C, supersaturation >0.367), whereas ⟨003⟩||ND films with coarser crystals (f8–15 μm = 0.597) originate in thermodynamic regimes of growth (T = 350 °C, supersaturation independent). Interestingly, Σ3 coincident site lattice (CSL)/twin boundaries are controllably incorporated in the ⟨110⟩||ND films (f = 0.337), whereas ⟨003⟩||ND films only possesses high-angle crystal interfaces (HACIs, f = 1.0). The morpho-structural evolution of the crystal assembly under electro-chemo-mechanical stimuli is rooted in crystal tectonics and corelated anisotropic ionic diffusion differences. Stochastic analysis of microstructures of electrochemically cycled films via electron backscatter diffraction (EBSD) and Raman spectroscopy indicates interface-, size-, and texture-dependent degradation modes. On electrochemical cycling, the ⟨003⟩||ND electrode degrades by both intercrystal and intracrystal cracking (13.3% retention), whereas the ⟨110⟩||ND electrode is only susceptible to intercrystal cleavage (89.2% retention). The cracks initiate at local lithiation heterogeneities near coarser crystals and always propagate along HACIs, with all the CSL boundaries remaining mechanically robust. Our discoveries highlight how careful orchestration of orientation and interfaces leads to unique chemomechanical stabilization strategies. 

Silicon is an emerging anode material due to its high lithium storage capacity. While some commercial batteries now include silicon particles, porous three-dimensional (3D) scaffolded silicon electrodes may enable higher silicon loading by accommodating the silicon volume expansion during lithiation without significant electrode swelling. However, the electrochemomechanical response of silicon films on metal scaffolds remains poorly understood due to the complex scaffold morphology. We explore the role of scaffold curvature in the cycling behavior of silicon films and show that different curvatures exhibit distinctive failure modes. Negative curvature leads to crack opening from tensile and compressive stresses. Positive curvature induces tensile stress-driven buckling. Zero curvature exhibits fragmentation. The electrode morphology and chemistry for these systems are evaluated via scanning transmission electron microscopy with energy-dispersive X-ray spectroscopy (STEM-EDS). COMSOL Multiphysics simulations support that the electrochemo-mechanics of silicon are curvature-dependent. These findings point toward design strategies for 3D architected silicon anodes with improved cycling integrity. 

Ion transport is essential to energy storage, cellular signaling, and desalination. Polymers have been explored for decades as solid-state electrolytes by either adding salt to polar polymers or tethering ions to the backbone to create less flammable and more robust systems. New design paradigms are needed to advance the performance of solid polymer electrolytes beyond conventional systems. Here, the role of a helical secondary structure is shown to greatly enhance the conductivity of solvent-free polymer electrolytes using cationic polypeptides with a mobile anion. Longer helices lead to higher conductivity, and random coil peptides show substantially lower conductivity. The macrodipole of the helix increases with peptide length leading to larger dielectric constants. The hydrogen bonding of the helix also imparts thermal and electrochemical stability, while allowing for facile dissolution back to monomer in acid. Peptide polymer electrolytes present a promising platform for the design of next generation ion transporting materials. 

We demonstrate focusing as well as imaging using diffractive microoptics, manufactured by two-photon polymerization grayscale lithography (2GL), that have been 3D printed into porous silicon oxide. While typical doublet lens systems require support structures that hold the lenses in place, our optics are held by the porous media itself, decreasing both the fabrication time and design constraints while increasing the optically active area. Compared to the typical two-photon polymerization fabrication process, 2GL offers better shape accuracy while simultaneously increasing throughput. To showcase 2GL manufactured optics in porous media, we fabricate singlet diffractive lenses with a diameter of 500 µm and numerical apertures of up to 0.6. We measure the intensity distribution in the focal plane, and along the optical axis. Furthermore, we design and fabricate a doublet lens system for imaging purposes with a diameter of 600 µm and thinner than 60 µm. We examine the imaging performance with a USAF 1951 resolution test chart and determine the resolution to be 287 lp/mm. 3D printing in porous SiO₂thus holds great promise for future complex and unconventional microoptical solutions. 

Redox-active colloids (RACs) represent a novel class of energy carriers that exchange electrical energy upon contact. Understanding contact-mediated electron transfer dynamics in RACs offers insights into physical contact events in colloidal suspensions and enables quantification of electrical energy transport in nonconjugated polymers. Redox-based electron transport was directly observed in monolayers of micron-sized RACs containing ethyl-viologen side groups via fluorescence microscopy through an unexpected nonlinear electrofluorochromism that is quantitatively coupled to the redox state of the colloid. Via imaging studies, using this electrofluorochromism, the apparent charge transfer diffusion coefficientD_CTof the RAC was easily determined. The visualization of energy transport within suspensions of redox-active colloids was also demonstrated. Our work elucidates fundamental mechanisms of energy transport in colloidal systems, informs the development of next-generation redox flow batteries, and may inspire new designs of smart active soft matter including conductive polymers for applications ranging from electrochemical sensors and organic electronics to colloidal robotics.