To be honest, looking at the papers, research, and John B. GoodEnough’s and Maria’s background, this is 100% possible, and will be coming to market in the near future.
Glass electrolytes are mainly formed using lihtium salts, such as lithium hydroxide, lithium chloride, or if you wish for an inferior electrolyte, lithium carbonate actually(it is possible due to how the molecules are actually arranged in the glass electrolyte matrix).
They are then doped with barium to allow for much lower degradation during fast charging and super fast charging scenarios.
The main draw of this electrolyte is not as much as cost or safety, but rather, the ease of manufacturing.
Problems require smart solutions:
1. To lower cost and boost energy density at the same time, Tesla engineered aluminium canned 21700 cells. This allowed for slightly lower internal resistance, higher gravimetric energy density, and the use of a lower cost chemical formula while still retaining very high energy density.
2. Single crystal NCA/NMC electrodes. While this does decrease energy density a bit(less active material per surface are and volume), this allows for a huge increase in cycle life, due to the fact that larger crystals are easier to make with less imperfections, and are just more durable.
3. Glass electrolytes. This lowers internal resistance, costs, boosts cycle life, and allows for more efficient use of active material, along with possible use with exotic materials like silicon to boost capacity even further.
TLDR: Fun times are ahead. The future is now.