Conversion reactions: a new pathway to realise energy in lithium-ion battery—review

Abstract

Rechargeable lithium-ion batteries of today operate by an electrochemical process that involves intercalation reactions that warrants the use of electrode materials having very specific structures and properties. Further, they are limited to the insertion of one Li per 3D metal. One way to circumvent this intrinsic limitation and achieve higher capacities would be the use of electrode materials in which the metal-redox oxidation state could reversibly change by more than one unit. Through the discovery of conversion or displacement reactions, it is possible to reversibly change by more than one unit. Further, the need for materials with open structures or good electronic ionic conductivity is eliminated, thus leading to a new area in materials for lithium ion battery. In this paper, we present a review enlightens new reaction schemes and their potential impact on applications.

Supercritical-fluid synthesis of FeF2 and CoF2 Li-ion conversion materials

“…The presence of amorphous carbon is also indicated in the XRD profile (shown 50 in figure 2), displaying a broad (20 -35° 2θ), bending region, a feature often characteristic of non-graphitic carbon types. The presence of carbon is further confirmed by Raman analysis, displayed in figure 4, which shows the D and G bands characteristic of sp 3 and sp 2 carbon types. …”

Microwave hydrothermal synthesis of high performance tin–graphene nanocomposites for lithium ion batteries

“…Carbon-based materials are the commercial anode materials for Li-ion batteries [1] with a limited theoretical capacity of 372 mAh g À1 , which cannot meet the demand for high specific capacities. Metal and metal oxides, such as silicon (Si) [2], tin (Sn) [3,4], cobalt oxide (Co 3 O 4 ) [5e8], and nickel oxide (NiO) [6,8e10], have been considered as promising alternative anode materials for reversible lithium storage.…”

Review on Synthesis, Characterizations, and Electrochemical Properties of Cathode Materials for Lithium Ion Batteries

“…Among various studies of fluorinated, fluorinated solvents are the most studied since it's used for increasing the safety and stability in LIB [183][184][185][186]. Different fluorine-doped intercalation cathodes are produced from fluorine which has been used as a dopant like layered transition metal oxyfluorides (Li 1+x excellent features on charge/discharge cycling compared to LiNiO 2 and showed enhanced in the capacity retention during cycling [188][189][190].…”

“…However, in the past and due to metal fluorides characteristic such as insulating nature and apparent irreversibility in structural conversion [175], it has been ignored as rechargeable cathode materials for lithium batteries. Malini et al [186] reported two ways to exploit the electrochemical efficiency of metal fluorides: first one, by mixing metal fluorides with conducting carbon materials to improve electrical conductivity and the second one, mechanical ball milling of metal fluoride to reduce the particle size [194][195][196][197]. VF 3 and TiF 3 are also transition metal fluoride, they demonstrated their effectiveness with Li and generated as high as 500-600 mAh/g [175].…”