Pumped thermal energy storage (PTES) is a grid-scale energy management technology that stores electricity in the form of thermal energy. A number of PTES systems have been proposed using different thermodynamic cycles, including the Brayton cycle, the Rankine cycle and transcritical cycles. This talk proposes to employ the Brayton cycle together with liquid storage media (as opposed to packed beds of solid particles), and finds that employing a gas-gas regenerator is useful to adapt the cycle to the operating temperature ranges of candidate liquid materials and to improve the work ratio of the cycle. Because the cycle performance is very susceptible to heat exchanger losses, emphasis is put on employing highly-effective heat exchangers.