A Soft Chemistry Approach to Coating of LiFePO₄ with a Conducting Polymer

Abstract

No carbon added: Using the intrinsic oxidative power of LiFePO4/FePO4 combined with the reinsertion of lithium ions, the formation of the conducting polymer poly(3,4‐ethylenedioxythiophene) (PEDOT) at the solid surface is demonstrated (see picture). The resulting composites have very promising electrochemical properties in rechargeable lithium batteries; in particular, they allow for the elimination of carbon additives.

Carbon-Coated Perovskite BaMnO3 Porous Nanorods with Enhanced Electrocatalytic Perporites for Oxygen Reduction and Oxygen Evolution

“…[21,29] To further improve the catalytic performance of this product, we try to coating a thin layer of carbon on the surface of the BaMnO 3 nanorods, inspiring from the excellent works of lithium ion batteries and supercapacitors. [16,17] Fig. 3 shows the electrocatalytic performances of carbon-coated BaMnO 3 nanorods for both ORR and OER, which demonstrate a marked improvement.…”

“…Cu, Ag, carbon and conducting polymers are currently utilized as coating materials. [16,17] Especially, many works have reported that surface modification with a nanometer-thick layer coating of proper materials is proven to be effective in further enhancing the electrocatalytic activity and transport properties as well as stability against electrolyte and durability of materials. [13] Among different coating materials, the most attractive coating is carbon, which has been widely used as surface modification technique for cathode and anode materials in the field of energy storage and conversion.…”

Nanostructured conductive polymers for advanced energy storage

“…The LiFePO 4 -PEDOT composites exhibited greatly improved rate capability (125 mA h g À1 at 10 C) and power density. 26 As the modification materials for anodes or cathodes, nanostructured conductive polymers have some important advantages, such as providing effective paths for electronic transport and Li ion diffusion, enhanced conductivity and electrochemical activity, but some shortcomings are also associated, such as an increase in undesirable reactions and potentially more complicated processing procedures.…”

Heterogeneous Nanostructured Electrode Materials for Lithium-Ion Batteries – Recent Trends and Developments

“…However, coating LiFePO 4 with homogeneous polymer thin layer is still very difficult. This problem can possibly be solved by the soft chemistry approach reported by Lepage et al (2011), which relies on the intrinsic oxidation power of Li 1-x FePO 4 rather than on an external oxidant as the driving force for the polymerization process, as shown in Figure 7a. The polymerization propagation requires the reinsertion of lithium into the partially delithiated LiFePO 4 , as well as the transport of Li + ions and electrons through the deposited polymer coating like PEDOT.…”

“…Specific capacities as high as 165 mAh/g at 0.2 C, 133 mAh/g at 7 C, and 123 mAh/g at 10 C are obtained in C-LFP/7 wt.% PANI composite. (Lepage et al, 2011) Other means have also been used to synthesize polymer/LiFePO 4 composites, including electropolymerization from a suspension of LiFePO 4 particles (Boyano et al, 2010), polymerization using a chemical oxidant in the presence of the particle (Wang et al, 2005), or formation of a colloidal suspension of the polymer immediately before the introduction of LiFePO 4 particles (Murugan et al, 2008). However, coating LiFePO 4 with homogeneous polymer thin layer is still very difficult.…”