Production and Characterisation of Fibre-Reinforced All-Solid-State Electrodes and Separator for the Application in Structural Batteries

Abstract

The electrification of the air transport sector demands for an energy storage that adds as little volume and weight to the overall system as possible. Regarding this so-called structural battery, composites enable the storage of electrical energy in commonly used load bearing fibre composite structures. A structural battery composite can store electrical energy while bearing mechanical loads, thus reducing parasitic mass and volume. In this study, structural cathodes were prepared by slurry coating carbon fibres with lithium iron phosphate (LFP), polyethylene oxide (PEO), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and carbon black. For the structural anodes, the carbon fibres were utilised as active material and slurry coated with PEO and LiTFSI. These structural electrodes as well as a structural separator were characterised by electrochemical cycling. With 139mAh/g, the structural cathodes demonstrated good utilisation of the active material. The carbon fibres used in the anode exhibited capacities of up to 92mAh/g. High irreversible lithium losses were observed, which are attributed to the poor electrolyte wetting behaviour of the carbon fibres. A structural battery demonstrator with a lithium metal anode was realised and reached a maximum specific energy of 64Wh/kg with respect to electrode and separator weight.

The Next Frontier in Energy Storage: A Game-Changing Guide to Advances in Solid-State Battery Cathodes

“…The study also highlighted that the state of charge (SOC) has a significant impact on the internal resistance of the battery, affecting its overall performance [30]. Vogt et al [31] explored the production and characterization of fiber-reinforced all-solid-state electrodes using LiFePO4 and found that the material demonstrated good utilization of the active material with capacities of up to 139 mAhg -1 (see Figure 2). .…”

“…Specific discharge capacity of cathode half cells with a structural separator cycled at 80 °C and 0.1C. The cells with the cathode and separator compressed at a higher pressure achieved capacities of maximum 139 mAhg −1 and, therefore, the best capacities of all investigated cells (Reprinted with permission from ref [31],. Copyright 2022, Batteries-MDPI).…”

Improvement of Cycle Stability for Graphite-Based Lithium-Ion Batteries via Usage of Phenyl Methanesulfonate as an Electrolyte Additive

“…The lithium-ion battery (LIB) as a reliable energy storage device has dramatically affected the world thanks to its high energy density and voltage along with its superior cycle stability. They are extensively utilized in portable devices such as cell phones and laptop computers and also in electric vehicles (EVs), which are useful to decrease environmental pollutions [3][4][5][6]. LIBs are commonly made up of a graphite anode and a transition metal oxide cathode, which are soaked in an organic electrolyte and separated by a separator [2,7].…”

“…G − H + Li + + e − → G − Li + 0.5H 2 (4) Various strategies are employed to cover the active sites to diminish irreversible capacity loss. One of these beneficial avenues is the physical coating of graphite materials with a protective layer like a metal oxide.…”