In this study, we describe combustion-processed high-quality Li-AlO x thin films and their implementation in In- 2 O 3 synaptic transistors by a low temperatures (300 °C) water-based method. The resulting synaptic transistors presented a superior electrical performance at a low operating voltage of 3 V, with a positive threshold voltage of 0.5 V, a subthreshold swing of 0.21 V/decade, an On/Off ratio of 1.5×10 5 , and a mobility value of 87 cm 2 V −1 s −1 . Counterclockwise hysteresis was observed in the transfer curve and the synaptic transistor was employed to perform synaptic emulation. Long-term and short-term synaptic depression and potentiation behavior were emulated.