Preparation and Structural Investigation of Olivine Structured LiFePO4

Li-ion batteries are generally a type of rechargeable battery that stores energy due to reversible reduction of Li-ions and have high gravimetric and volumetric capabilities. These are widely utilised in portable electronic gadgets, electric cars, and grid-scale energy storage systems because of its high energy density, low self-discharge rate, and extended cycle life. An anode, a cathode, and an electrolyte with a separator in between comprise a Lithium-ion battery (LIB). The conductivity of ions and electrons among the different parts of a battery directly affects its electrochemical characteristics. In order to improve the thermal stability, cycle performance, and operational safety of the battery, an improvement in the cathode material is required. In lithium-ion batteries, the cathode material is often divided into three main categories: layered oxides, spinel oxides, and polyanion type. Among these, polyanion Lithium Iron Phosphate (LiFePO4) has olivine orthorhombic structure with space group Pnma, is a very promising material owing to its good thermal stability (stable up to 400 °C), high theoretical capacity (170 mAhg−1), wide operating temperature (−30 °C to 60 °C), excellent cycle life (over 2000) and comparatively low cost. In the present work, we have synthesised LiFePO4 by means of solid-state reaction process and structural investigations carried out through XRD, FT-IR, and surface morphological investigation using SEM-EDAX technique. Electrical characterisation was done using EIS technique.