Charge-discharge Mechanism of LiCoPO₄ Cathode for Rechargeable Lithium Batteries

Electrochemical Delithiation/Relithiation of LiCoPO4: A Two-Step Reaction Mechanism Investigated by in Situ X-ray Diffraction, in Situ X-ray Absorption Spectroscopy, and ex Situ 7Li/31P NMR Spectroscopy

“…In Situ XAS. First Co K-edge X-ray absorption nearedge structure (XANES) measurements on LiCoPO 4 were reported by Okada et al 40 These measurements, though only performed ex situ on three (initial, charged, and discharged) samples, already hinted qualitatively at a partially reversible redox reaction of Co. For the first time, the present work sheds further light on the reversibility of the electrochemical reaction processes occurring in the course of delithiation and relithiation by collecting in situ XAS spectra of the Co K-edge during the initial full cycle. As charging of LiCoPO 4 commences, one would expect an oxidation of the Co 2+ to Co 3+ which would cause a shift of the XANES spectra to higher energies.…”

Benzylamine-directed growth of olivine-type LiMPO4nanoplates by a supercritical ethanol process for lithium-ion batteries

“…Lithium-ion batteries (LIBs) with high intrinsic energy densities have become promising energy storage systems for future applications in stationary rechargeable batteries and full electric vehicles. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Since the rst commercial products manufactured by Sony in 1992, the Li-ion battery technologies have been developed to meet the requirements of large-scale applications. Among a variety of inorganic materials, lithium transition metal phosphates LiMPO 4 (M ¼ Fe, Mn, Co, or Ni) with an olivine structure have been considered as the most promising cathode materials for rechargeable Li-ion batteries owing to their low cost, high capacity, stability, efficiency and long-term durability.…”

“…[8][9][10][11] The lithium cobalt phosphate (LiCoPO 4 ) and lithium nickel phosphate (LiNiPO 4 ) are also promising since these orthophosphates offer both at high potential (at approximately 4.8 V and 5.1 V versus Li/Li + ), good theoretical capacity ($167 mA h g À1 ) and smaller structure volume change. [12][13][14] However, the major drawback with the LiCoPO 4 and LiNiPO 4 cathodes is the sluggish kinetics of the lithium ion and electronic transport. Therefore, efforts have been made in recent years on improvement of the electrochemical performance of LiCoPO 4 (ref.…”

Unique synthesis of sandwiched graphene@(Li0.893Fe0.036)Co(PO4) nanoparticles as high-performance cathode materials for lithium-ion batteries

“…15 LiCoPO 4 has advantages of at high potential (at approximately 4.8 V vs. Li/Li + ), good theoretical capacity (167 mA h g À1 ) and smaller structure volume change. 2,16 However, there are some drawbacks and unsolved problems for this high-voltage cathode material. The practical use of LiCoPO 4 is precluded by its poor rate cycling ability related to the inherently low electrical conductivity (<10 À9 S cm À1 ) and Li + ionic conductivity.…”