LiMnPO₄ Nanoplates with In-Situ Growth of a sp²-Carbon Surface Layer from a Liquid Precursor, Phase Stability, and Tailored Impedance Properties

Title:LiMnPO₄ Nanoplates with In-Situ Growth of a sp²-Carbon Surface Layer from a Liquid Precursor, Phase Stability, and Tailored Impedance Properties

Volume: 7 Issue: 1

Author(s): S. K. Sharma, T. Majumder, M. Dewan and S. Ram*

Affiliation:

• Materials Science Centre and School of Nanoscience and Technology, Indian Institute of Technology, Kharagpur -721 302,India

Keywords: Energy storage materials, hybrid electric vehicles, hydrothermal synthesis, nanoplates, selfassemblies, solid electrolytes.

Abstract: Background: Olivine structured LiMnPO₄ is a pioneering energy-storage material of Li⁺-ion batteries. Its synthesis in a shape of small plates (large free-surfaces) bonding over a C-sp² surface layer is demanded in harvesting its functional properties.

Objective: In situ synthesis of grafted LiMnPO₄ of nanopaltes with a C-sp² surface layer, with tailored impedance properties.

Method: A simple hydrothermal reaction is explored in a solution LiOH·H₂O, MnSO₄·H₂O and H₃PO₄ with sodium dodecyl sulphate (a surfactant) to synthesize LiMnPO₄ of small plates. A phase pure LiMnPO₄ is obtained in 8-12 h heating a precursor solution at 150°C in an autoclave, and then washing a recovered powder in hot water.

Results: The sample LiMnPO₄ contains nanoplates of a P_mnb orthorhombic crystal structure, 20-40 m²/g surface area, 30-40 nm thickness, and self-assemblies. The lattice parameters a = 0.6104 nm, b = 1.0468 nm and c = 0.4758 nm describe a marked 0.43 % lattice expansion over the bulk phase, with an enhanced aspect ratio c/a = 0.7795 above the bulk value 0.7777, which likely promotes the charge-carrier dynamics. In the HRTEM images, the LiMnPO₄ plates wear a GO-surface layer of a conductive 2D-network with sp²-C electrons. Uniquely, a cell made of the sample yields largely enhanced (i) conductivity of Li⁺ ions and electrons at a 10-6 S-cm^-1 scale and (ii) Li⁺ diffusion coefficient 3.291x10^-14 cm²s^-1 at room temperature.

Conclusion: The results describe LiMnPO₄ nanoplates with an inbuilt surface C-sp² layer extend fast charge diffusion kinetics useful for powerful Li⁺- ion batteries.

Cite this article as:

Sharma K. S., Majumder T., Dewan M. and Ram S.*, LiMnPO₄ Nanoplates with In-Situ Growth of a sp²-Carbon Surface Layer from a Liquid Precursor, Phase Stability, and Tailored Impedance Properties, Current Physical Chemistry 2017; 7 (1) . https://dx.doi.org/10.2174/1877946806666161115142518

DOI https://dx.doi.org/10.2174/1877946806666161115142518	Print ISSN 1877-9468
Publisher Name Bentham Science Publisher	Online ISSN 1877-9476