The structural change during electrochemical cycling in full-cell system has been investigated by neutron diffraction method and the full-cell consists of spinel-lithium manganese oxide cathode and graphite anode. The structural variation has been monitored by in-situ neutron diffraction technique at different state of charges (SOCs), and the obtained data were compared with ex-situ powder neutron diffraction patterns. Phase transitions for lithiated/delithiated graphite can clearly explain that the intercalated lithium ions in graphite are not perfectly extracted during a delithiaion process. The content of LiC12 phase increases as an increase in electrochemical cycle numbers, and the lattice parameter of LiMn2O4 also decreases due to the reduction of the amounts of Li ions, which can be reversibly intercalated/deintercalated into/from the structure.

Keywords: Neutron diffraction, In-situ, LiMn2O4, Structural change