Lithiated iron phosphate and thin-film amorphous silicon are used for positive and negative electrodes of lithium-ion battery, correspondingly. Laboratory samples of flexible lithium-ion batteries are manufactured and tested with load 0.4 mA. This load corresponded to current density of 1 A/g for negative electrode and 23 mA/g for positive one. The samples were cycled in the voltage range 2.3 to 3.48 V. Energy density of the sample amounted up to 100 W·h/l. Capacity fading was ca. 0.08% per cycle for 500 cycles.