How would you explain the importance and environmental impact of developing a gelled cell in relation to the current cell model?  What is the difference between half cells versus lithium and the impact they have in determining the stability and capacity of the batteries?

The current processes used for the battery fabrication use water based wet casting for the anode and the N-methyl pyrrolidone (NMP) based wet casting for the cathode. The evaporation and the recycling of these solvents during the electrodes drying explains 50% of the energy used in the battery fabrication. The process proposed to make gelified batteries do not use any of these solvents and then avoid the energy expenses associated with the solvent processing. In other words, it cuts by half the CO2 footprint of the fabrication process. The toxicity issues associated with the use of NMP are also avoided completely.

On the other hand, the key elements for the fabrication of a gelified battery (electrode and separator) are the specific binders developed and patented by SOLVAY and the processing know-how jointly developed and patented by SOLAY and CEA.

Within the whole process, the stability and capacity of the batteries is determined by the half-cells and the lithium as follows, half-cell vs lithium is one of the experimental protocols used to investigate each electrode separately. With this protocol it is possible to measure for each electrode its capacity (in mAh) and the evolution of the electrode potential vs the reference lithium electrode. This protocol also gives a first indication of the lifetime of each electrode by observing the capacity fading of the electrode during the half cell cycling trials.

However, the energy density of a battery is increased by the following factors which are the capacity of both electrodes and the potential difference between the anode and the cathode.  When we analyze the battery performance, it is difficult to associate the observed effects to the anode or to the cathode because both behaviors are mixed in the resulting battery performance. To investigate and understand the behavior of a specific electrode, it is necessary to combine the electrode under development with a well-known electrode like, for example, a lithium metal electrode.