It may be preferred that the inorganic particle mixture comprises at least compounds of lithium and tellurium. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium and bismuth. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium and zinc. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium, zinc and bismuth. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium, sodium, bismuth and zinc. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium and cerium. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium, cerium and bismuth. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium, cerium and zinc. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium, zinc, cerium and bismuth. It may be preferred that the inorganic particle mixture comprises at least compounds of lithium, tellurium, sodium, bismuth, cerium and zinc.

Inorganic Particle Mixture—Particle Size

The particle size of the inorganic particle mixture may not be particularly limited in some embodiments of the present invention.

However, the inventors have found that inorganic particle mixtures with certain particle size distributions are surprisingly useful. Control of the particle size distribution is therefore important in some aspects of the invention.

The invention may relate to embodiments in which the inorganic particle mixture has a particle size distribution in which either
D₁₀≤0.41 μm;??(a)