Macroporous LiFePO4 as a cathode for an aqueous rechargeable lithium battery of high energy density

Abstract

Our former research found that lithium metal coated with a gel polymer electrolyte and LISICON film can be stable in aqueous electrolytes to carry out lithium plating and dissolution, and is a good anode for high energy density aqueous rechargeable lithium batteries (ARLBs). Here we prepared three-dimensionally macroporous LiFePO₄ and used it as the cathode to build another ARLB in 0.5 mol l⁻¹ Li₂SO₄ aqueous solution. Its stable output voltage is 3.32 V with excellent cycling performance and good rate capability. Its energy density is much higher than that of previously reported traditional ARLBs, and is also higher than those for traditional lithium ion batteries based on graphitic carbon/organic electrolyte/LiFePO₄. Its safety and reliability are also very good. The results suggests that the chemistry of post lithium ion batteries is of great promise for practical applications in electric vehicles.