One-Step Low-Temperature Route for the Preparation of Electrochemically Active LiMnPO₄ Powders

Abstract

Pure and well-crystallized LiMnPO 4 powders were obtained by a direct precipitation route in an aqueous medium at 373 K. A thermodynamic study of the system Li + /Mn(II)/phosphate/ H 2 O identified a pH range in which LiMnPO 4 precipitation was the most probable. From these theoretical considerations, the olivine-type compound precipitation turned out to be straightforward, i.e., no further thermal treatment was needed. A systematic study of the influence of synthesis parameters enabled tailoring of the size of the as-obtained particles. The smallest precipitated particles (∼100 nm) led to a global improvement of the electrochemical behavior when used in lithium batteries, consisting in lowering the polarization and enhancement of the reversible capacities (∼70 mAh/g at C/20). A two-phase Li extraction/insertion mechanism was identified, using the potential intermittent titration technique (PITT) and in situ X-ray diffraction, between LiMnPO 4 and the delithiated phase MnPO 4 , indexed in the space group Pmnb with unit cell parameters a ) 5.93(2) Å, b ) 9.69(6) Å, and c ) 4.78(1) Å.

Carbonate anion controlled growth of LiCoPO4/C nanorods and its improved electrochemical behavior

“…A c c e p t e d M a n u s c r i p t 4 studied LiMPO 4 (M = Fe, Co, Mn, Ni) cathodes [9][10][11][12]. Despite these advantages, there are challenges associated with the practical application of LiCoPO 4 [9,10,[13][14][15][16] such as poor conductivity and slow lithium transport kinetics.…”

Enhanced electrochemical performance of <30 nm thin LiMnPO4 nanorods with a reduced amount of carbon as a cathode for lithium ion batteries

“…To improve the electrochemical kinetics, several groups, including previous work by us, reported the enhanced electrochemical properties, combining both, reduced particle size of LiMnPO 4 and carbon coating [12][13][14][15]. Nanosized LiMnPO 4 provides the shorter lithium ion diffusion path within a single particle compared to micronsized LiMnPO 4 [16]. Most highly performing LiMnPO 4 materials were achieved by adding a large amount of carbon (15-30 wt%) in order to increase the electronic conductivity [12][13][14][15][17][18][19][20].…”

Improved kinetics and stabilities in Mg-substituted LiMnPO4

“…Recent experimental 4 and theoretical studies 5 Most efforts to improve the kinetic performance of LiMnPO 4 have focused on particle size reduction, [6][7][8][9][10] which increases the rate capability and utilization, but inevitably decreases the volumetric energy density of the electrode. Larger surface area also enhances the reactivity of the material toward the electrolyte, thereby raising safety and lifetime concerns.…”