3D interdigitated microbattery architectures (3D-IMA) are fabricated by printing concentrated lithium oxide-based inks. The microbatteries are composed of interdigitated, high-aspect ratio cathode and anode structures. Our 3D-IMA, which exhibit high areal energy and power densities, may find potential application in autonomously powered microdevices.

Versatile and readily available battery materials compatible with a range of electrode configurations and cell designs are desirable for renewable energy storage. Here we report a promising class of materials based on redox active colloids (RACs) that are inherently modular in their design and overcome challenges faced by small-molecule organic materials for battery applications, such as crossover and chemical/morphological stability. RACs are cross-linked polymer spheres, synthesized with uniform diameters between 80 and 800 nm, and exhibit reversible redox activity as single particles, as monolayer films, and in the form of flowable dispersions. Viologen-based RACs display reversible cycling, accessing up to 99% of their capacity and 99 ± 1% Coulombic efficiency over 50 cycles by bulk electrolysis owing to efficient, long-distance intraparticle charge transfer. Ferrocene-based RACs paired with viologen-based RACs cycled efficiently in a nonaqueous redox flow battery employing a simple size-selective separator, thus demonstrating a possible application that benefits from their colloidal dimensions. The unprecedented versatility in RAC synthetic and electrochemical design opens new avenues for energy storage.

The purpose of this study was to improve the forming techniques and parameters for producing spherical ceramic beads using sodium alginate as a sacrificial template. This process has the potential of producing beads for applications such as stress-wave propagation of granular media, beads for milling, catalyst support, and encapsulation of drugs, as well as water filtration. This simple, inexpensive, and environmentally friendly approach to producing spherical ceramic beads using bead-forming equipment occurs when a flat-tipped needle produces droplets that cross-link, forming green bodies upon contact with CaCl 2 solution. An exchange of ions takes place where sodium alginates substitute their Na + for Ca 2+ to form semirigid bodies. Spherical ceramic beads using 50 wt% alumina suspension with 0.04 wt% polyacrylate dispersant are produced when: the viscosity of the slurry is below 0.3 PaÁs, the surface tension of the gelling solution is below 50 mNÁm, and the distance of the nozzle tip to the reacting solution is~3 cm. This approach for producing ceramic beads using alginates will allow its use for any type of ceramic material, changing its chemical composition, and controlling the microstructure and shape of the beads.L. Gauckler-contributing editor Manuscript No. 33430.