Abstract

A new all-solid-state structural energy storage device, which integrates a Na+-based ferroelectric glass electrolyte with metallic electrodes and current collectors and thin-ply carbon-fiber laminates¹ to create a coaxial multifunctional beam, is proposed. This new design optimizes beam-type structures of general cross-sections by incorporating an electrochemical system capable of storing electrical energy, while also acting as a load-carrying element with appropriate mechanical performance. Electrochemical testing has demonstrated its ability to perform three-minute charges to one-day discharges (70 cycles), as well as long-lasting discharges (>40 days at 1 mA), with an energy density of 56.2 Wh.L−1 and a specific energy of 38.0 Wh.kg−1, taking into account the total volume and weight of the structural cell². Mechanical tests have also shown that the coaxial structural battery can withstand severe inelastic deformation without affecting its functionalities, see figure 1. Additionally, the absence of alkali metals and liquid electrolytes make this coaxial structural battery a safe and viable alternative for energy storage in applications where traditional lithium-ion batteries may not be suitable. However, micro-CT scan, see figure 2, performed on mechanically tested coaxial structural batteries revealed some drawbacks of this innovative configuration: i) the granular nature of the proposed electrolyte does not guarantee any mechanical contribution to axial tensile loads, and ii) the metal-carbon interface was observed to be the bottleneck for the structural integrity of the beam-type battery. These results motivate two parallel research lines: the evaluation of the mechanical and electrochemical properties of Li-free all-solid-state electrolytes identifying the Nasicon as the most suitable candidate, and the mechanical characterization and functionalization of metal-carbon interfaces.

Figure 1. Beam-type structural battery loaded in three-point bending.

Figure 2.  μCT scan: (left) Transverse section, (right) axial scan of mechanically tested structural battery.

References

1. A. Arteiro, C. Furtado, G. Catalanotti, P. Linde, P.P. Camanho, Thin-ply composites: a review, Composites Part A, v.132 (2020).
2. F. Danzi, P.P. Camanho, M.H. Braga, An all-solid-state coaxial structural battery using sodium-based electrolyte, Molecules, v.26 (2021).

Location: Building 19, Level 3, Hall 1-2.