Cork: Enabler of sustainable and efficient coaxial structural batteries

Structural batteries aim to advance to 'massless' energy storage units. Here we report an electrode-less coaxial battery with a cork-internal shell, CFRP(+)/cork/Cu/Na2.99Ba0.005ClO/Al (-), where CFRP is carbon fiber reinforced polymer. The cell may, alternatively, solely have a cork external shell cork/Cu(+)/Na2.99Ba0.005ClO/Al(-). Cork is a cellular material with a negative CO2 footprint, light, elastic, impermeable to gases or liquids, and an excellent thermal insulator. Cork was used tandemly with a CFRP shell, working as the positive current collector to enhance the structural batteries' properties while allowing a giant electrostatic performance in conjunction with the Na+ solid-state ferroelectric injected between the Al negative collector and the cork. Cork was shown a polar dielectric. This 'minimalist' cell may perform without copper making the cells even more sustainable. Neither cells contain traditional electrodes, only one or two current collectors. The cells perform from 0 to >50 degrees C. The maximum capacity of the cork/Cu (+)/Na2.99Ba0.005ClO/Al(-) cells is similar to 110 mAh.cm(-2) (outer shell) with < I > approximate to 90 mu A cm(-2), < V > approximate to 0.90 V, V-max approximate to 1.1-1.3 V, I-max approximate to 108 mu A cm(-2), and a constant resistance discharging life (>40 days). The novel family of cells presented may also harvest waste heat and thermal energy at a constant temperature as their potential and current increase with temperature. Conversely, rising potentials boost the cells' temperature, as expected from pyroelectrics, as shown herein.

Automated summary

Structural batteries aim to develop "massless" energy storage devices. A novel electrode-less coaxial battery with a cork-internal shell and CFRP/Cu/Na2.99Ba0.005ClO/Al configuration was reported. The battery utilizes cork, a lightweight, elastic, impermeable to gases or liquids, and excellent thermal insulator material, in tandem with CFRP to enhance the battery's properties. The cells demonstrate high electrostatic performance and can operate without copper, making them more sustainable.