The present work is a study of the thermal properties and electrochemical stabilities of N-ethyl-N-methylmorpholinium bromide ([Mor1,2][Br]), N-butyl-N-methylmorpholinium bromide ([Mor1,4][Br]), N-octyl-N-methylmorpholinium bromide ([Mor1,8][Br]), N-dodecyl-N-methylmorpholinium bromide ([Mor1,12][Br]), and N,N-dihydroxyethylmorpholinium bromide ([DHEMor][Br]). The melting points, decomposition temperatures, and electrochemical stabilities of the salts were measured by DSC (differential scanning calorimetry), TGA (thermogravimetric analysis), and CV (cyclic voltammogram), respectively. All salts were decomposed below approximately 230.00 ℃ and their melting points were above 100.00 ℃ except [DHEMor][Br], which melted at 75.17 ℃. [DHEMor][Br] appeared to possess the most wide liquid-phase range between melting point and decomposition temperature. The electrochemical windows of salts ranged from 3.3 V for [Mor1,8][Br] to 3.6 V for [Mor1,4][Br] and thus did not show any noticeable variation with cations used for salt synthesis.