APPLICATION OF MODIFIED CONDUCTIVE ADDITIVES AND AQUEOUS BINDERS IN POSITIVE ELECTRODES BASED ON LITHIUM IRON PHOSPHATE FOR LITHIUM ION BATTERIES

Abstract

 Positive electrodes play a significant role in operation of lithium-ion batteries. The inactive constituents of the electrode coating, electrically conductive additive and binder, are key components for efficient operation of active material. Therefore, minimizing the toxicity of some and the synthesis or modification of others remain an urgent topic for increasing the energy intensity of lithium-ion batteries, which is the main goal of this work.  Synthesis and modification of nanostructured carbon electrically conductive additives and the study of their influence on the specific characteristics of the electrode in combination with water-soluble polymers.  During the research, the optimal compositions of the positive electrode were found: 1) using aqueous polymers, 2) with the addition of synthesized graphene oxide obtained by the Hummers method; 3) with the addition of modified carbon nanotubes obtained by the Hummers method.  Graphene oxide synthesized by the Hummers method and carbon nanotubes reduced by the same method give a discharge specific capacity of more than 150 mAh/g and 140 mAh/g, respectively, with an active material theoretical capacity of 160-170 mAh/g, those using them instead of commercial conductive additives can significantly improve the specific characteristics of positive electrodes. This is due to an increase in the kinetics of lithium ion transfer inside the active material due to many structural defects due to synthesis, in addition, they are better dispersed in water, and it is also possible to obtain thick coating layers.