Research Article Electrochemical Analysis of Architecturally Enhanced LiFe 0.5 Mn 0.5 PO 4 Multiwalled Carbon Nanotube Composite Sabelo Sifuba, Shane Willenberg, Usisipho Feleni, Natasha Ross , and Emmanuel Iwuoha SensorLab, Chemical Science Building, University of the Western Cape, Bellville 7535, Cape Town, South Africa Correspondence should be addressed to Natasha Ross; nross@uwc.ac.za Received 3 June 2020; Revised 25 November 2020; Accepted 9 February 2021; Published 20 February 2021 Academic Editor: Valery Khabashesku Copyright © 2021 Sabelo Sifuba et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In this work, the effect of carbon on the electrochemical properties of multiwalled carbon nanotube (MWCNT) functionalized lithium iron manganese phosphate was studied. In an attempt to provide insight into the structural and electronic properties of optimized electrode materials, a systematic study based on a combination of structural and spectroscopic techniques was conducted. e phosphor-olivine LiFe 0.5 Mn 0.5 PO 4 was synthesized via a simple microwave synthesis using LiFePO 4 and LiMnPO 4 as precursors. Cyclic voltammetry was used to evaluate the electrochemical parameters (electron transfer and ionic diffusivity) of the LiFe 0.5 Mn 0.5 PO 4 redox couples. e redox potentials show two separate distinct redox peaks that correspond to Mn 2+ /Mn 3+ (4.1VvsLi/Li + )andFe 2+ /Fe 3+ (3.5 V vs Li/Li + ) due to interaction arrangement of Fe-O-Mn in the olivine lattice. e electrochemical impedance spectroscopy (EIS) results showed LiFe 0.5 Mn 0.5 PO 4 -MWCNTs have high conductivity with reduced charge resistance. is result demonstrates that MWCNTs stimulate faster electron transfer and stability for the LiFe 0.5 Mn 0.5 PO 4 framework, which demonstrates to be favorable as a host material for Li + ions. 1. Introduction e phosphor-olivine-type lithium manganese phosphate (LMP) materials have enjoyed extensive research over the past decade and is now a worldwide commercial product [1], having been labelled as strong contenders for series of high- power electrodes for lithium batteries. Among the com- pounds of the olivine family, LiMPO 4 with M � Fe, Mn, Ni, orCo;onlyLiFePO 4 is currently used as the active element of positive electrodes for energy storage systems. In compar- ison with lithium cobalt oxide (LCO), they are more cost- effective and provide excellent-safely characteristics in terms of thermal runaway [2–5]. e isostructure of LiFe 0.5 Mn 0.5 PO 4 is obtained by partial substitution of Mn by Featoms.AccordingtoastudydonebyZhaoandcoworkers, LiFe0.5Mn0.5PO4/C in aqueous rechargeable lithium bat- teries can reach discharge capacities of 120 mAh g −1 [6–9]. However, LiFe 0.5 Mn 0.5 PO 4 has been reported to be sensitive to moisture, causing a loss of active lithium from the olivine structure under formation of Li 3 PO 4 on the particle surface and thus lowering the material’s energy density [10–17]. In addition, LiFe 0.5 Mn 0.5 PO 4 is known for the problem of manganese dissolution like other Mn-containing cathode materials [17–20]. For LiFe 0.5 Mn 0.5 PO 4 , a relation between the presence of traces of water in the battery and manganese dissolution has been found [21]. ese facts indicate that caution must be taken upon construction of LiFe 0.5- Mn 0.5 PO 4 to prevent poor electrochemical characteristics. Further limitations include poor electronic conductivity (<10 −9 S cm −1 ) which leads to high impedance and low rate of Li + ion diffusion (10 −14 –10 −16 cm 2 S −1 ) [22, 23]. Various methods have been investigated to improve conductivity of LiFePO 4 , reducing the particle size in nanorange [24] and coating with conductive agents [25]. However, this work reports for the first time the synergy of MWCNTs with LiFe 0.5 Mn 0.5 PO 4 . Cyclic voltammetry is an excellent tool in modern analytical chemistry. In this technique, a cyclic linear potential sweep is applied to the electrode and the resulting current is recorded. Information about the kinetics and mass transport can be obtained by probing the CV Hindawi Journal of Nanotechnology Volume 2021, Article ID 6532348, 8 pages https://doi.org/10.1155/2021/6532348