Three-dimensional bicontinuous ultrafast-charge and -discharge bulk battery electrodes

Abstract

Rapid charge and discharge rates have become an important feature of electrical energy storage devices, but cause dramatic reductions in the energy that can be stored or delivered by most rechargeable batteries (their energy capacity). Supercapacitors do not suffer from this problem, but are restricted to much lower stored energy per mass (energy density) than batteries. A storage technology that combines the rate performance of supercapacitors with the energy density of batteries would significantly advance portable and distributed power technology. Here, we demonstrate very large battery charge and discharge rates with minimal capacity loss by using cathodes made from a self-assembled three-dimensional bicontinuous nanoarchitecture consisting of an electrolytically active material sandwiched between rapid ion and electron transport pathways. Rates of up to 400C and 1,000C for lithium-ion and nickel-metal hydride chemistries, respectively, are achieved (where a 1C rate represents a one-hour complete charge or discharge), enabling fabrication of a lithium-ion battery that can be 90% charged in 2 minutes.

Evaluating the performance of nanostructured materials as lithium-ion battery electrodes

“…These materials can also be filled with electrolytes that are liquid or polymer based, forming interpenetrating networks. Recent demonstrations have shown that ultrafast-charging batteries can be fashioned by controlling porosity in active materials [517][518][519][520][521]. The downside is the severe reduction in specific energy due to the porosity, but the technology may prove useful for large surface area applications.…”

A colloidoscope of colloid-based porous materials and their uses

“…Because the nanoparticles are fully embedded in the matrix, they do not dislodge from the structure, and the efficiency is stable even after hundreds of cycles ( Figure 28B). 62 Alternatively, active electrode materials can easily be grown on conducting supports to produce a layered structure, 26,415,416,425,465 as shown in Figure 29. With hierarchical structures, the charge can quickly travel from the active site to the conducting matrix, where it can be collected before recombination.…”

Microstructural tunability of co-continuous bijel-derived electrodes to provide high energy and power densities

“…Recently, Zhang et al have shown that inverse opal structures consisting of conductive metal backbones and electrolytically active phases can offer rapid charge and discharge rates while maintaining a fairly modest energy density. 13,14 However, the particular pore conguration of an inverse opal (spherical pockets connected by small interstitial windows) does not lend itself to the level of morphological control needed to independently tune the electrode's capacity and power density while also conserving the required co-continuity to avoid current constriction in the charge carrier transport pathways. The fabrication technique also limits the height of the electrode to $15 mm, restricting the total amount of stored energy in these systems.…”