Model-Based Design of High Energy All-Solid-State Li Batteries with Hybrid Electrolytes

Abstract

As the aircraft industry becomes more committed to sustainable aviation, hybrid-electric propulsion systems containing batteries with higher specific energy have attracted attention as a means to reduce fuel consumption. Future aircraft could benefit from next-generation chemistries like oxide-based solid-state Li battery (SSB) technologies. However, producing and evaluating a wide range of design parameters for maximizing the specific energy of SSB experimentally is both time- and resource-intensive. Physics-based modeling promises to identify optimal designs for battery cells with respect to high specific energy in a more time and cost-efficient manner. Here, we applied a pseudo-two-dimensional model for the model-based evaluation of Li-SSB with various (hybrid) electrolytes to elucidate which solid electrolyte performs well with present electrode technology and which one has the potential to become an attractive alternative with more development. After identifying design variables to improve SSB with the help of sensitivity analysis, a genetic algorithm is used to predict the optimal design parameters to achieve higher specific energy. The study reveals that SSB based on 12.7 vol% of LLZTO is the best option under present manufacturing constraints. Hybrid electrolytes based on 10 wt% of LATP could be promising for future aircraft with further improvements in SSB manufacturing process.

Conceptual Design of Solid-State Li-Battery for Urban Air Mobility

“…We use a hybrid electrolyte with 12.7 vol% LLZTO, as this configuration yielded the best performance among hybrid electrolytes at a relatively high C-rate, i.e., 1C. 22 The electrolyte properties of this hybrid electrolyte are based on reported experimental data in Ref. 24, which accounts for any impurity or degradation effects present in real material.…”

“…Following Wolff's work, our group developed an ASSB model for hybrid electrolytes, including polymer and oxide electrolytes, to estimate the optimal electrode design using a global optimisation algorithm to attain higher specific energy. 22 We found that a hybrid electrolyte based on 12.7 vol% of garnet, i.e. LLZTO, based on the current manufacturing limitations of ASSB, is the best choice.…”

“…Our recent study concentrated on the thickness of the separator and various potential materials for it. 22 In the current work, we have applied the separator results from our previous study, and we have given particular attention to the cathode side. Here we examine the impact of different cathode compositions and distributions on the battery performance and propose the best electrode structure.…”

Are batteries fit for hybrid-electric regional aircraft?

“…The numerical approach to the ASS-LA modelling consists of adapting the P2D electrochemical model to the solid (or hybrid) electrolyte. The main changes affect the mass conservation and the charge balance in the electrolyte [22]. The model is extended with a microstructure surrogate model to derive the effective macroscopic parameters.…”

“…Two sets of calculations are performed. The first set, reported in [22], aims at identifying hybrid polymer-ceramic solid electrolytes with high GED and optimising the best (V1 in Figure 5) for three cell designs: energy, power or balanced for 1C discharge. For V1, a maximum GED of 450 Wh/kg at cell level can be reached, but with very limited power output.…”