Akademik Veri Yönetim Sistemi
SUSTAINABLE ENERGY & FUELS, cilt.1, sa.1, ss.1-20, 2026 (SCI-Expanded, Scopus)
This study investigated aluminum oxide (Al2O3) surface coatings on lithium nickel manganese cobalt oxide
(NMC811) cathodes using a wet chemical process based on ethanol-dissolved aluminum ethoxide
(Al(OEt)3). Three coating concentrations, 1, 2, and 3 wt% Al precursor relative to the NMC811 mass, were
synthesized and referred to as NMC811@AlO-1, NMC811@AlO-2, and NMC811@AlO-3, respectively. The
workflow encompassed structural and surface characterizations of the coated samples, followed by
electrochemical evaluation in half- and full-cell configurations. FTIR confirmed Al–O bond formation,
while XRD and Raman spectroscopy verified that the NMC811 lattice structure remained unchanged after
coating. Furthermore, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy
(TEM-EDX) confirmed the successful deposition of the Al2O3 layer. Time-of-flight secondary ion mass
spectrometry (ToF-SIMS) analysis revealed Al3+ ion diffusion into the grain interiors, indicating a potential
impact on the electrochemical performance of the electrodes. Electrochemical tests showed that all the
coated samples exhibited improved stability, with NMC811@AlO-3 (3 wt% coating) achieving the best
capacity retention in half cells. In the second phase, full cells were formed using pre-lithiated graphite,
graphene, and graphene oxide (GO) anodes, for which pre-lithiation conditions were optimized. Among
all combinations, the NMC811@AlO-3/GO full cell demonstrated the highest initial discharge capacity
(183 mAh g−1) and the best cycling retention (80.1% after 250 cycles at C/2). These results suggest that
a 3 wt% Al2O3 coating, combined with a GO anode, provides the most promising pathway toward highperformance
full-cell systems.