Surface-modified and sulfide electrolyte-infiltrated LiNi0.6Co0.2Mn0.2O2 cathode for all-solid-state lithium batteries

Sulfide-based all-solid-state lithium batteries (ASSLBs) with high-voltage Ni-rich layered cathodes have shown great potential in energy storage systems. However, the application of ASSLBs is hindered by severe interface issues and poor solid–solid contact between cathodes and sulfide electrolytes. In this work, a suitably thin Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) coating (0.41 mS cm −1 ) is introduced onto the surface of single-crystal LiNi 0.6 Co 0.2 Mn 0.2 O 2 particles to mitigate interface side reactions. Subsequently, sheet-type electrodes are fabricated by the infiltration of Li 10 GeP 2 S 12 to fill the voids and achieve highly dense solid–solid contact, thus preventing contact loss. The Li 10 GeP 2 S 12 -infiltrated ASSLBs with a LAGP buffer layer display a high initial discharge capacity of 141.5 mAh g −1 at 0.05 C and ultrastable cycling for 100 cycles at 0.1 C. An effective fabrication method for highly dense electrodes is proposed in this work, which provides a new direction for scalable industrial production.