Kharchikova Evgeniya Vital'evna RussiaSaratov Saratov State University, 83, Astrakhanskaya St., Saratov, 410012магситрантb1708637@mail.ru0000-0002-5905-5992 Author's articles Electrochemical System of LiTi₂(PO₄)₃ | 1 M Aqueous Li₂SO₄ | LiFePO₄ and Prototypes of the Lithium-Ion Battery Based on it