New Solid-state Battery Technology Is Coming Again

- Aug 16, 2019-

It is reported that a cheap, large-capacity solid-state battery has the potential to realize the practical concept of the past .

The solid-state battery manufacturer is the Belgian research institute IMEC, and Panasonic is also involved in the development of electrolyte materials. IMEC announced in June that it has developed a solid electrolyte lithium-ion rechargeable battery with a volumetric energy density of 425 h / L (Figure 1). It is assumed that lithium iron phosphate (LFP) is used as the positive electrode active material, and metallic lithium is used as the negative electrode active material.

The most important feature of the IMEC battery is its manufacturing process (Fig. 2). The same as the current electrolyte battery, the first is the formation of the positive electrode, and then the liquid electrolyte is infiltrated into the positive electrode material.

Outline of Manufacturing Process of Entire Solid Battery of IMEC (a): First, a positive electrode material is formed on a current collector, and a liquid material as an electrolyte precursor is incorporated therein, and solidified to form a negative electrode layer or the like. Unlike the conventional solid electrolyte, it has the advantage (b) that the conventional lithium ion battery manufacturing apparatus can be utilized to some extent.

The difference is that the electrolyte is dried to become a solid to form a negative electrode. It is also easy to implement, and it is only necessary to slightly change the existing electrolyte battery device at the time of mass production, and it can be used well, so even if it is an all-solid battery, it is not necessary to make a high investment. In fact, IMEC has basically established the technology for mass production of large batteries. The company plans to prototype a battery with a size of A4 and a capacity of 5 Ah in 2019.

Since the electrolyte initially permeates into the corners of the electrode in a liquid manner, the phenomenon that the contact area between the electrode and the solid electrolyte is small and the interface resistance is extremely high is hard to occur in the solid battery. From your point of view, which battery will be more marketable in the future?