text: In 2018, researchers from the Moscow Institute of Physics and Technology (MIPT), the Technological Institute for Superhard and Novel Carbon Materials (TISNCM), and the National University of Science and Technology (MISIS) announced a prototype using 2-micron thick layers of Ni foil sandwiched between 200 10-micron diamond converters. It produced a power output of about 1 μW at for power density of 10 μW/cm. At those values, its energy density would be approximately 3.3 Wh/g over its 100-year half-life, about 10 times that of conventional electrochemical batteries. This research was published in April 2018 in the Diamond and Related Materials journal.