Acetylene black-embedded LiMn0.8Fe0.2PO4/C composite as cathode for lithium ion battery

Electrochemical properties of iron substituted lithium manganese phosphate prepared by sol-gel method

“…It shows a merged semicircle at high-frequency region and a straight line at low-frequency region. The semicircle corresponds to the charge-transfer resistance, and the line is related to the diffusion of lithium ions [13]. For LiMn 0.4 Fe 0.6 PO 4 , the resistance is smaller obviously, which suggests that Fe substitution makes a positive influence on the properties of the active reaction process and the diffusion of lithium ions.…”

Surfactant-assisted solid-state synthesis of 6LiMn0.8Fe0.2PO4·Li3V2(PO4)3/C nanocomposite for lithium-ion batteries

“…The slope of the straight line is proportional to the Li + diffusion coefficient. 13,42 By comparing the diameter of the semicircles and the slope of the straight lines, it was found that 6LMFP$LVP/C exhibits smaller interface impedance and much faster Li + diffusion than LMFP/ C and LMP/C. This demonstrates that the electronic and ionic conductivity of 6LMFP$LVP/C are better than those of LMFP/C and LMP/C and also claries the fast rate capability of 6LMFP$LVP/C.…”

“…4 Recent reports have proven that the electrochemical kinetics of LiMnPO 4 can be remarkably improved by partially replacing Mn with Fe. Various LiMn 1Ày Fe y PO 4 (0 < y < 1) solid solutions, such as LiMn 0.9 Fe 0.1 PO 4 , 11,12 LiMn 0.8 Fe 0.2 PO 4 , [13][14][15][16] LiMn 0.6 Fe 0.4 PO 4 , [17][18][19] LiMn 0.5 Fe 0.5 PO 4 ,20 LiMn 0.4 Fe 0.6 PO 4 , [21][22][23] etc., exhibit much better electrochemical performance than the pristine LiMnPO 4 . Yang et al 24 synthesized a LiMn 0.8 Fe 0.2 PO 4 /C composite using a co-precipitation method, which provided a specic capacity of 160.6 mA h g À1 at 0.05C.…”

Improving the electrochemical kinetics of lithium manganese phosphate via co-substitution with iron and cobalt

“…Based on the investigation of XPS, the possible mechanism of improved Li + intercalation/deintercalation in LiMn 0. 9 …”

“…However, LiMnPO 4 suffers from poor Li + intercalation/deintercalation kinetics caused by the intrinsically low ionic and electronic conductivity from the heavy polaronic holes localized on the Mn 3+ sites, and the interface strain between the LiMnPO 4 and MnPO 4 phase [6][7][8]. In response, strategies including particle-size minimization, electrically conductive coating, forming LiMn 1Àx Fe x -PO 4 solid solutions and substitutional doping have been applied in efforts to improve the electrochemical performance [9][10][11]. Despite the combined advantages of relative high electrical conductivity of LiFePO 4 and relative high voltage of LiMnPO 4 , the overall energy density of Mn-Fe solid solutions decreases with the increase of Fe content owing to the lower equilibrium potential of the Fe 2+ /Fe 3+ redox potential.…”