High Energy Density Single Crystal NMC/Li6PS5CI Cathodes for All-Solid-State Lithium Metal Batteries


Cathode cross section after charging

To match the high capacity of metallic anodes, all-solid-state batteries (ASSBs) require high energy density, long-lasting composite cathodes such as Ni-Mn-Co (NMC) based lithium oxides mixed with a solid-state electrolyte (SSE).



Researchers from this department, funded by The Faraday Institute and using equpment purchased using funding from the Sir Henry Royce Institute tackled the issue whereby in practice the cathode capacity typically fades due to NMC cracking and increasing NMC/SSE interface debonding, because of NMC pulverisation (which is only partially mitigated by the application of a high cell pressure during cycling).  


Using smart processing protocols they reported a single crystal particulate LiNi0.83Mn0.06Co0.11O2 and Li6PS5CI SSE composite cathode with outstanding discharge capacity of 210 mAh g-1 at 30oC.


A first cycle coulombic efficiency of >85%, and >99% thereafter was achieved despite a 5.5% volume change during cycling.  A near-practical discharge capacity at a high areal capacity of 8.7 mAh cm-2 was obtained using a novel asymmetric anode/cathode cycling pressure of only 2.5 MPa/0.2 MPa.  


Read the full paper in Chem Rxiv.