Characterization of Al-doped spinel LiMn2O4 thin film cathode electrodes prepared by Liquid Source Misted Chemical Deposition (LSMCD) technique

A novel process called Liquid Source Misted Chemical Deposition (LSMCD) was used to synthesize Al-doped LiMn2O4 cathode films for Lithium microbatteries. The cathode films were characterized by XRD, SEM, cyclic volatmmetry, and charge/discharge test. LiMn1.8Al0.2O4 film crystallized at 800 deg. C in rapid thermal annealing (RTA) for 5 min under oxygen atmosphere exhibited more improved electrochemical rechargeability than spinel LiMn2O4 film because the substitution of Al3+ for Mn3+ increased Mn-O bonding strength in the spinel framework and suppressed the two-phase behavior of the unsubstituted spinel during the intercalation/deintercalation that is the origin of the failure mechanism in the 4 V region. As a result, LiMn1.8Al0.2O4 film showed an initial discharge capacity of 52 μAh/cm2 μm and no capacity fade over 100 cycles