The nature of the processes that occur when electrodes modified with complexes [M(Schiff)] (M = Ni, Pd, Pt; Schiff denotes four-dentate Schiff base ligands) are irradiated with visible light for the...
As a cathode material for lithium-ion batteries, lithium iron phosphate (LiFePO4, LFP) successfully transitioned from laboratory bench to commercial product but was outshone by high capacity/high voltage lithium metal oxide chemistries. Recent changes in the global economy combined with advances in the battery pack design brought industry attention back to LFP. However, well-recognized intrinsic drawbacks of LiFePO4 such as relatively low specific capacity and poor electronic and ionic conductivity have not yet been fully mitigated. Integration of electrochemically active electron-conducting polymers (EAECPs) into the cathode structure to replace conventional auxiliary electrode components has been proposed as an effective strategy for further performance improvement of LFP batteries. In this review, we show how various combinations of polymer properties/functions have been utilized in composite LiFePO4 electrodes containing EAECP components. We present recent advances in the cathode design, materials, and methods and highlight the impact of synthetic strategies for the cathode preparation on its electrochemical performance in lithium-ion cells. We discuss advantages and limitations of the proposed approaches as well as challenges of their adoption by the battery manufactures. We conclude with perspectives on future development in this area.
18 December 2016 in Russian Journal of Electrochemistry
Graphene nanostructures (GNSs) are among the most promising materials for producing supercapacitors. However, GNSs are still not used in creating supercapacitors due to the impossibility of obtaining large volumes of high-quality material at an acceptable cost. In our previous works, we have shown the possibility of synthesizing large volumes of few-layer graphene (FLG, the number of layers is not more than five) from cyclic biopolymers under conditions of self-propagating high-temperature synthesis (SHS). Using the SHS process makes it possible to synthesize large volumes of FLG without Stone–Wales defects. This work is devoted to the study of the possibility of using FLG synthesized under the conditions of the SHS process in the creation of supercapacitors. It was found that the synthesized FLG makes it possible to obtain better results than using classical materials, namely activated carbon (AC). It was found that the sample based on FLG had a higher specific capacitance of 65 F × g−1 compared to the sample from AC, the specific capacitance of which was 35 F × g−1; for a speed of 5 mV × s−1, these values were170 and 64 F × g−1, respectively. The drop in capacitance over 1000 cycles was 4%, indicating a sufficiently high FLG stability, allowing us to consider FLG as a prospective material for use in supercapacitors.