Institute of Physics has been one of the leading research center of condensed matter physics (a fancy way of saying solid state physics) in China
It seems to me that "condensed matter" is a wildly and long accepted terminology by the science community. It includes a lot other matters including but not limited to liquid.
The term itself is serious, even though the usage by this particular company may be just out of fancy marketing strategy, just like someone in this forum tried to blend the old composite material into meta material for bragging right.
On the other hand, the company may be serious with naming their battery. That means their battery isn't pure solid, but a mix of solid and liquid mediums.
From a layman's perspective, there is either solid or liquid, so condensed matter does sound wired to the point of "marketing gimmick", but it may be more accurate and honest than it seems.