| 摘要 |
A positive electrode material has a nominal stoichiometric formula of Li_(1+2/y)Co_(1-x-y-z-d)Si_zFe_xM_yM′_d(PO_4)_(1+y/2). M is at least one kind of trivalent cation selected among Cr, Ti, Al, Mn, Ni, V, Sc, La and/or Ga; M′ is at least one kind of divalent cation selected among Mn, Ni, Zn, Sr, Cu, Ca and/or Mg; y satisfies 0<y<=0.10; and x satisfies 0<=x<=0.2. Using double composition exchange of LiCoPO_4 allows discharge capacity retention of the LiCoPO_4 which is monosubstituted with Fe-, while increasing about 100-130 mAh/g of discharge capacity. Additional composition exchange of including Si increases the cycle life and remarkably improves coulombic efficiency up to 97 to 100% in the cycle rate of C/3. |
