Spinel Cathode Research Articles

Comparison of Failure Mechanisms in Lithium Manganese Oxide and Lithium Nickel Manganese Oxide Spinel Cathodes

LiNi0.5Mn1.5O4 (LNMO), with an operating voltage of 4.9 V vs Li/Li+ and a theoretical capacity of 147 mAhg-1 and LiMn2O4 (LMO), with an operating voltage of 4.1 V vs Li/Li+ and a theoretical capacity of 133 mAhg-1 are both highly attractive cathode material for secondary lithium ion batteries (LIB) owing to their low material cost, and excellent rate capability due to their spinel structure. Over the last two decades, much research effort has been focused on gaining a fundamental understanding of the failure mechanisms of these two electrodes. Dissolution and deposition of manganese was long thought to be the principle failure mechanism of LMO electrodes while for LNMO, because of its high operating voltage, electrolyte decomposition and concurrent degradative reactions at the electrode/electrolyte interfaces were thought to be the main culprit. In this study we have systematically investigated the failure mechanisms of LMO & LNMO electrodes. Full cells were built using graphite as the negative electrode and 1.2 M LiPF6 in EC: EMC, 3:7 as the electrolyte and were cycled at room temperature and at elevated temperature. Several quantitative and qualitative analysis techniques were conducted to investigate the correlation between capacity loss and Mn ion deposition, acidic species generation, solid electrolyte interphase (SEI) degradation, impedance growth as these cells cycled at different temperatures.

Cr‐doped LiCoMnO 4 cathode with high phase purity and promoted electrochemical performance

To improve the electrochemical performances of high voltage LiCoMnO4 spinel cathode material at 5.3 V, Cr doped LiCoMn1-xCrxO4 (x = 0, 0.025, 0.050, 0.075) materials were synthesized by a one-step solid-state at 750°C. Rietveld refinement results showed that the phase purity of spinel is promoted with the increase in Cr concentration, which can be explained by the strong CrO bond that reduces oxygen deficiency and eliminates Li2MnO3 impurity phase during the synthesis process. Such change in phase purity further causes the improvement in specific capacity, and the 5.0%Cr doped sample displays the best result with a value of 123.0 mAh/g at 0.1°C and 93.3 mAh/g at 10°C. For a comparison, the pristine sample only releases a capacity of 112.6 mAh/g at 0.1°C and 54.8 mAh/g at 10°C. Improved capacity retention, from 83.1% to 90.1% after 100 cycles at 1°C, is also observed due to the suppressed volume change during the redox process after the incorporation of Cr cations in the lattice. Promoted rate performance, attributed from the improved Li ion diffusion coefficient, is also confirmed in the experiment. The improvement of those electrochemical properties could be explained by high-phase purity and superior structural stability benefited from Cr-doping. Novelty statement LiCoMn1-xCrxO4 (x = 0, 0.025, 0.050, 0.075) materials were synthesized by a one-step solid-state at 750°C, Chromium had been confirmed to reduce oxygen loss during LiCoMnO4 synthesis due to high oxygen affinity of Cr, which improves phase purity. As a result, the specific capacity was increased. Cr-doping enhances the structural stability so that capacity retention was promoted due to higher bond energy of CrO than MnO; rate performance was also enhanced due to the improved diffusion coefficient.

Twin boundary defect engineering improves lithium-ion diffusion for fast-charging spinel cathode materials

Defect engineering on electrode materials is considered an effective approach to improve the electrochemical performance of batteries since the presence of a variety of defects with different dimensions may promote ion diffusion and provide extra storage sites. However, manipulating defects and obtaining an in-depth understanding of their role in electrode materials remain challenging. Here, we deliberately introduce a considerable number of twin boundaries into spinel cathodes by adjusting the synthesis conditions. Through high-resolution scanning transmission electron microscopy and neutron diffraction, the detailed structures of the twin boundary defects are clarified, and the formation of twin boundary defects is attributed to agminated lithium atoms occupying the Mn sites around the twin boundary. In combination with electrochemical experiments and first-principles calculations, we demonstrate that the presence of twin boundaries in the spinel cathode enables fast lithium-ion diffusion, leading to excellent fast charging performance, namely, 75% and 58% capacity retention at 5 C and 10 C, respectively. These findings demonstrate a simple and effective approach for fabricating fast-charging cathodes through the use of defect engineering.

Thermally Aged Li-Mn-O Cathode with Stabilized Hybrid Cation and Anion Redox.

Though low-cost and environmentally friendly, Li-Mn-O cathodes suffer from low energy density. Although synthesized Li4Mn5O12-like overlithiated spinel cathode with reversible hybrid anion- and cation-redox (HACR) activities has a high initial capacity, it degrades rapidly due to oxygen loss and side-reaction-induced electrolyte decomposition. Herein, we develop a two-step heat treatment to promote local decomposition as Li4Mn5O12 → 2LiMn2O4 + Li2MnO3 + 1/2 O2↑, which releases near-surface reactive oxygen that is harmful to cycling stability. The produced nanocomposite delivers a high discharge capacity of 225 mAh/g and energy density of over 700 Wh/kg at active-material level at a current density of 100 mA/g between 1.8 to 4.7 V. Benefiting from suppressed oxygen loss and side reactions, 80% capacity retention is achieved after 214 cycles in half cells. With industrially acceptable electrolyte amount (6 g/Ah), full cells paired with Li4Ti5O12 anode have a good retention over 100 cycles.

Molten salt synthesis of LiMn 1 . 2 Ni 0 . 3 Cr 0 . 1 Co 0 . 15 Al 0 . 23 La 0 . 02 O 4 as a positive electrode for lithium‐ion batteries

The molten salt synthesis method became an excellent synthesis technique to elaborate nanomaterials because of its meritorious advantages including low cost, easy to scale up, simple to operate, and environmental friendliness. For this reason, the compound LiMn1.2Ni0.3Cr0.1Co0.15Al0.23La0.02O4 was synthesized for the first time by molten salt method using NaCl as the salt and a nonstandard manganese source with metallurgical grade. The obtained cathode material was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transformer infra-red (FT-IR), and electrochemical characterization. XRD and FT-IR results confirm the stability and formation of pure spinel phase without any impurities. TEM images showed that the spinel synthesized phase consists of 77 to 135 nm-sized polyhedral nanoparticles. The cyclic voltammogram results showed that the synthesized spinel cathode material exhibits two-main redox peaks at 4.06/3.9 V and 3.1/2.8 V vs Li+/Li, which indicate the possibility of insertion of extra lithium in the spinel structure. Galvanostatic charge-discharge studies were also carried out showed that the prepared spinel material has two discharge plateaus in the potential window of 1.5 to 5 V and a discharge capacity of 179 mAh g−1 at 0.1 C, which is higher than the theoretical value which confirms the insertion of extra lithium in the spinel structure and enhance the capacity of the cathode material. The electrochemical impedance spectroscopy was performed, and the Li-ion diffusion coefficient was also calculated.

Insight Gained from Using Machine Learning Techniques to Predict the Discharge Capacities of Doped Spinel Cathode Materials for Lithium‐Ion Batteries Applications

The electrochemical potentials of spinel lithium manganese oxide (LMO) have long been plagued by the significant Mn3+ dissolution during long cycle discharging, resulting in rapid capacity fading and short cycle life. Although the doping mechanisms are effective in suppressing these reactions, the correlations of their effects on the material properties and the improved discharging performance still remain uncovered. In this study, seven machine learning (ML) methods are applied to a manually curated dataset of 102 doped LMO spinel systems to predict the initial discharge capacities (IC) and 20th cycle end discharge capacities (EC) from fundamental system properties like material molar mass and crystal structure dimension. Gradient boosting models achieved the best prediction powers for IC and EC with their errors estimated to be 11.90 and 11.77 mAhg−1, respectively. Besides, a higher formula molar mass of doped LMO can improve both capacities and additionally, a shorter crystal lattice dimension with a dopant with smaller electronegativity can slightly improve the value of the IC and EC, respectively. This study demonstrates the great potential of using ML models to both predict the discharging performance of doped spinel cathodes and identify the governing material properties for controlling the discharging performance.

A High-Voltage, Multi-Metal LiNi0.35Cu0.1Mn1.45Fe0.1O4 Spinel Cathode for Lithium Batteries

A LiNi0.35Cu0.1Mn1.45Fe0.1O4 spinel cathode exploiting the multi-metal approach and operating in a lithium battery at 4.7 V is prepared by co-precipitation of metal oxalates followed by annealing. Our investigation demonstrates that the designed electrode formulation including Ni, Cu, Mn and Fe may actually ensure suitable structural and morphological characteristics, as well as an extended stability in cells operating at 25 °C and 55 °C. Indeed, the LiNi0.35Cu0.1Mn1.45Fe0.1O4 cathode shows reversible capacities of 108 mAh g−1 at 0.75C and 91 mAh g−1 at 1.5C (where 1C is 147 mA g−1), with a retention between 84% and 80% after 200 cycles and coulombic efficiency values of about 99%. Notably, optimal cathode composition in terms of metals nature and content avoids material degradation upon cycling and enables stable operation in the lithium cell even at a temperature higher than 25 °C, with satisfactory retention of the initial capacity of 110 mAh g−1, i.e., 77%, after 200 cycles at 0.5C. Therefore, the strategy adopted herein is considered adequate for allowing practical battery application of the high-voltage spinel cathode.

Structural and Electrochemical Properties of the High Ni Content Spinel LiNiMnO4

This work presents a contribution to the study of a new Ni-rich spinel cathode material, LiNiMnO4, for Li-ion batteries operating in the 5-V region. The LiNiMnO4 compound was synthesized by a sol-gel method assisted by ethylene diamine tetra-acetic acid (EDTA) as a chelator. Structural analyses carried out by Rietveld refinements and Raman spectroscopy, selected area electron diffraction (SAED) and X-ray photoelectron (XPS) spectroscopy reveal that the product is a composite (LNM@NMO), including non-stoichiometric LiNiMnO4-δ spinel and a secondary Ni6MnO8 cubic phase. Cyclic voltammetry and galvanostatic charge-discharge profiles show similar features to those of LiNi0.5Mn1.5O4 bare. A comparison of the electrochemical performances of 4-V spinel LiMn2O4 and 5-V spinel LiNi0.5Mn1.5O4 with those of LNM@NMO composite demonstrates the long-term cycling stability of this new Ni-rich spinel cathode. Due to the presence of the secondary phase, the LNM@NMO electrode exhibits an initial specific capacity as low as 57 mAh g−1 but shows an excellent electrochemical stability at 1C rate for 1000 cycles with a capacity decay of 2.7 × 10−3 mAh g−1 per cycle.

Advances and Prospects of High-Voltage Spinel Cathodes for Lithium-Based Batteries.

Insertion compounds have been dominating the cathodes in commercial lithium-ion batteries. In contrast to layered oxides and polyanion compounds, the development of spinel-structured cathodes is a little behind. Owing to a series of advantageous properties, such as high operating voltage (≈4.7V), high capacity (≈135mAh g-1 ), low environmental impact, and low fabrication cost, the high-voltage spinel LiNi0.5 Mn1.5 O4 represents a high-power cathode for advancing high-energy-density Li+ -ion batteries. However, the wide application and commercialization of this cathode are hampered by its poor cycling performance. Recent progress in both the fundamental understanding of the degradation mechanism and the exploration of strategies to enhance the cycling stability of high-voltage spinel cathodes have drawn continuous attention toward this promising insertion cathode. In this review article, the structure-property correlations and the failure mode of high-voltage spinel cathodes are first discussed. Then, the recent advances in mitigating the cycling stability issue of high-voltage spinel cathodes are summarized, including the various approaches of structural design, doping, surface coating, and electrolyte modification. Finally, future perspectives and research directions are put forward, aiming at providing insightful information for the development of practical high-voltage spinel cathodes.

Physicochemical Design Principles Enabling High-Energy and -Power Low-Cost Na Storage Materials

Although Ni2+/Ni4+ double redox offers the possibility of high-energy-density manganese-based spinel cathode materials for sodium-ion batteries, their poor cyclability and power density, owing to i...

Unveiling decaying mechanism through quantitative structure-activity relationship in electrolytes for lithium-ion batteries

Understanding the decaying mechanism in lithium-ion batteries (LIBs) is critical to establishing a stable electrolyte system. Despite the advent of various novel electrolyte solvents designated for high-voltage LIBs, their working principles are not fully understood. Currently, oxidative decomposition of electrolytes is believed to be the major cause of capacity fade, and tremendous effort has been devoted to discovering a new electrolyte with enhanced anodic stability. However, the oxidative decomposition process cannot solely explain the rapid decay of some electrolyte systems with intrinsic high anodic stability when used with a high-nickel layered oxide cathode such as LiNi0.6Mn0.2Co0.2O2 (NMC622). In this report, a study of the quantitative structure-activity relationship was conducted to deepen the mechanistic understanding of the decay in high-voltage LIBs. The results obtained from the newly introduced molecular pair analysis and linear free-energy relationship (LFER) studies were highly consistent with the solvation-involved decaying mechanism in a high-nickel layered oxide cathode cycling at high voltage (> 4.5 V vs. Li/Li+). There was no evidence correlating the solvation ability of electrolyte solvents with the decay of a high-nickel layered oxide cathode cycling at a relatively low voltage (< 4.3 V vs. Li/Li+), nor with the high-voltage spinel cathode LiNi0.5Mn1.5O4 (LNMO). Undoubtedly, the unveiled mechanistic insight provides a critical guideline for the development of an appropriate electrolyte system targeting different high-voltage cathode materials.

Synthesis, Modification, and Lithium‐Storage Properties of Spinel LiNi0.5Mn1.5O4

AbstractLithium‐ion batteries (LIBs) are currently widely applied in many aspects of life, but with the development, the capacity of lithium‐ion batteries can no longer meet the needs. One of the dominant factors to restricting the capacity of LIBs is the cathode materials. Among the derivatives of spinel cathode LiMn2O4 (LMO), LiNi0.5Mn1.5O4 (LNMO) has become one of the research promising cathode materials in the current LIBs due to its high working voltage (4.7 V) and large theoretical specific capacity (147 mAh g−1). However, the short cycle life of LNMO during the electrochemical process limits its large‐scale commercial applications. Thus, it is necessary to summarize and discuss the recent development of LNMO. Through comparison with LiMn2O4, the structure, electrochemical properties of LNMO, influence of Mn on the performance of LNMO, and the capacity fading mechanism are analyzed and discussed in detail. We also summarize the modification methods of LNMO and the influence of preparation methods on the structure and performance of LNMO. Finally, some prospects of LNMO cathode are put forward. This Review article can provide helpful references for future design and construction of LNMO.

Detailed redox mechanism and self-discharge diagnostic of 4.9 V LiMn1.5Ni0.5O4 spinel cathode revealed by Raman spectroscopy

Raman spectroscopy captures the changes in Ni redox states during lithiation of high voltage LMNO cathode. A fast, easy and reliable measure of the self-discharge phenomenon is accessible thanks to appropriate Raman spectra analysis.

Evaluating the impact of additives and lithium salts on the performance of spinel cathode material LiMn2O4

LiMn2O4 spinel structure was considered as the cathode material to replace LiCoO2 for high voltage lithium-ion batteries, however, its main drawback was poor cycling due to dissolution of manganese and structural instability. One of the effective solutions is to find out a suitable electrolyte composition and additive to reduce the manganese dissolution and to prevent the side reaction between the electrode material and the electrolyte. In this study, we investigated the impact of using fluoroethylene carbonate (FEC), vinyl carbonate (VC), lithium bis(oxalato)borate (LiBOB) as additives for the electrolyte of 1 M LiPF6/EC:DMC (1:1) and different salt such as: LiBF4, LiClO4 and LiTFSI for commercial carbonate solvent of EC:DMC (1:1) on the improvement of the cyclic stability and electrochemical performance of LiMn2O4 electrodes. The results showed that the addition of FEC did not affect the initial capacity but increased significantly the cycle stability of the material. In particular, the discharge capacity maintained 91% of initial value after 20 cycles in the electrolytes containing 2 %wt and 3 %wt FEC, respectively. However, further increase of FEC content induced the polarization of the charge discharge curves as well as the increase of the electrode - electrolyte interface resistance which were responsible for the cycling performance decline. Among tested salts, LiClO4 was the best electrolytic one for EC:DMC (1:1) based-electrolyte that enhanced the initial discharge capacity roughly 20 mAh/g. In addition, preliminary results on the full-cell of graphite||LMO achieved the discharge capacity of 87.09 mAh/g (at C/5) and 73.52 mAh/g (at C/2) which is about 66.99 % the initial discharge capacity obtained at C/5 of the half-cell LMO|Li).

The effect of vanadium doping on the cycling performance of LiNi0.5Mn1.5O4 spinel cathode for high voltage lithium-ion batteries

High voltage LiNi 0.5 Mn 1.5 O 4 (LMNO) spinel cathode has been attracting high interest due to its high energy density and cobalt-free chemistry. However, high temperature (50 °C) cycling behavior is not very good because of the electrolyte decomposition, metal dissolutions, and the formation of gas products. To improve the high-temperature cycling behavior of the LMNO spinel cathode, vanadium doping was employed. For this purpose, pristine LMNO, LiNi 0.45 Ti 0.1 Mn 1.45 O 4 , and LiNi 0.4 V 0.1 Mn 1.5 O 4 cathode materials were synthesized and their elevated temperature cycling behavior was compared. After 200 cycles, the 10% V-doped LMNO still has an excellent cycling performance of 99.5 mAh g −1 (capacity fade is 6.55%) at 50 °C and 1C-rate compared to 28.8 mAh g −1 pristine LMNO (capacity fade is 70.4%), and 84 mAh g −1 LiNi 0.45 Ti 0.1 Mn 1.45 O 4 capacity retention (capacity fade is 25.6%), respectively. These results showed that the V-doped LMNO design is the proper solution for high-temperature durability. • Increasing wt% doping percentage of vanadium causes nickel divanadate impurity. • Mn dissolution is not main capacity fade reason for LMNO. • Active lithium loss causes rapid capacity fade for V-doped LMNO//SiC full-cell.

Meticulous guard: The role of Al/F doping in improving the electrochemical performance of high-voltage spinel cathode

Spinel LiNi0.5Mn1.5O4, which is considered as one of the most attractive candidates for high energy density battery due to its high voltage platform over 4.7 V, suffers from the side reactions with electrolyte, strong oxidability of Ni4+ and therefore the complicated and frangible Solid Electrolyte Interfaces (SEI) layer that hinders the practical application of LiNi0.5Mn1.5O4. In this work, traditional co-precipitation method is applied and improved by anion and cation doping method to construct superior interface on the surface of LiNi0.5Mn1.5O4 to suppress side reactions especially at high temperature. Detailed properties including structure, morphology and electrochemical performance of pristine sample, single-doped and co-doped samples are probed. Physical characterizations reveal that the co-doped sample with regular octahedron has a moderate grain size and specific surface area between Al and F single doping, and holds the advantages of rate performance and capacity retention causing by Al doping and better stability under high temperature constructing by F. It exhibits the best capacity retention of 92% after 200 cycles under 55 °C, which is higher than that of the pristine sample (87%). Analysis of the electrode after cycling shows that doping reduces the thickness of the electrode interface film and the content of inorganic substances such as LiF to improve the interface characteristics and the high temperature cycling performance. This work has certain significance for the commercial application of LiNi0.5Mn1.5O4.

Development of Multivalent Electrolytes with a Wide Electrochemical Window and Their Applications

Multivalent (MV) ion batteries have been under intense scrutiny because the modeling effort predicted that a high Mg2+ diffusion mobility in spinel cathodes and a higher specific energy density can be achieved. Recently new cathodes have been tested against Mg, with novel cathodes such as layered oxides MoO2.8F0.2,1 MgCr2-xVxO4,2 and conversion-type cathodes.3 Previously chloride containing electrolytes4 were dominant in multivalent ion batteries because of their facile deposition and high Coulombic efficiency towards the anode. However, the corrosion issue of Cl- limits their application. Here we report the development of chloride-free multivalent salts with a weakly coordinating anion that shows exceptional electrochemical properties. Moreover, the passivation-free properties of these anions make them efficient in assessing the Mg2+ mobility inside a solid solution electrode. Further development on other multivalent cations will also be demonstrated. Together with cathodes, these electrolyte developments would pave the way for a holistic approach towards high energy density multivalent batteries.References T. Incorvati, L. F. Wan, B. Key, D. Zhou, C. Liao, L. Fuoco, M. Holland, H. Wang, D. Prendergast, K. R. Poeppelmeier, Chemistry of Materials 2015, 28, 17-20.J. Kwon, K.-C. Lau, H. Park, Y. A. Wu, K. L. Hawthorne, H. Li, S. Kim, I. L. Bolotin, T. T. Fister, P. Zapol, R. F. Klie, J. Cabana, C. Liao, S. H. Lapidus, B. Key, J. T. Vaughey, Chemistry of Materials 2019. DOI:10.1021/acs.chemmater.9b04206Pan, J. Huang, Z. Feng, L. Zeng, M. He, L. Zhang, J. T. Vaughey, M. J. Bedzyk, P. Fenter, Z. Zhang, C. Liao, Advanced Energy Materials 2016, 6.Pan, J. Huang, N. Sa, S. M. Brombosz, J. T. Vaughey, L. Zhang, A. K. Burrell, Z. Zhang, C. Liao, * Journal of The Electrochemical Society 2016, 163, A1672-A1677.-C. Lau, T. J. Seguin, E. V. Carino, N. T. Hahn, J. G. Connell, B. J. Ingram, K. A. Persson, K. R. Zavadil, C. Liao, * J. Electrochem. Soc. 2019, 166, A1510-A1519.

Investigation of Ethylene Carbonate Free Electrolyte for L4Ti5O12 Vs LiNi0.6Mn0.2Co0.2O2 Multi-Layer Pouch Cells

Lithium titanate (L4Ti5O12 or LTO) is a sought-after alternative in conjunction with high voltage capable cathodes to the graphite anode in lithium ion batteries for electric vehicle and stationary storage applications. LTO offers improved abuse tolerance due to elimination of lithium dendrite formation when compared to graphite, the zero-strain property which enables operation at high rates, wide operating temperature range, and long cycle life.1 The limitations of LTO include a low specific capacity that of which is half the capacity of graphite anode, significant gas generation, and a high working potential (1.55V vs Li0 /Li+). LTO pairing with various Li[NixMnyCo1-xy]O2 (NMC) materials appears interesting as it may offer improvements to the low specific capacity of the LTO material, when compared to cathode materials such as LMO or LCO2 without the complexities and numerous challenges still associated with spinel cathode materials. Herein we report on an electrolyte optimization study for the LiNi0.6Mn0.2Co0.2O2 (NCM622)//LTO electrode couple using multi-layer pouch cells, which focuses on ethylene carbonate (EC) free formulations, with the aim of reducing the amount of gas formed by the LTO anodes. References N. Takami, H. Inagaki, Y. Tatebayashi, H. Saruwatari, K. Honda, S. Egusa, J. Power Sources, 244, 469-475 (2013).N. Gauthier, C. Courrèges, J. Demeaux, C. Tessier, H. Martinez, J. Electrochem. Soc., 167, 040504 (2020).

Interphases Formation and Analysis at the Lithium–Aluminum–Titanium–Phosphate (LATP) and Lithium–Manganese Oxide Spinel (LMO) Interface during High‐Temperature Bonding

In this study, fabrication processes of solid electrolyte/cathode interfaces for their use in next‐generation all‐solid‐state lithium‐ion battery (LIB) applications are described. Standard lithium–aluminum–titanium–phosphate (LATP) solid electrolyte and lithium–manganese oxide (LMO) spinel cathode ceramic half cells are assembled using two all‐solid‐state methods: a) co‐sintering the cathode and electrolyte materials via field‐assisted sintering and b) field‐assisted high‐temperature bonding. The morphology and composition of the interfaces are analyzed by scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS). This study reveals that the formation of interphases can be significantly decreased by separately performing the densification and joining procedures. Electrochemical impedance spectroscopy (EIS) is applied to understand and determine the effect of the manufactured interfaces on the system conductivity. Based on the results, it is concluded that the high‐temperature bonding technique appears to be a suitable technique for future production of all‐solid‐state LIBs.

Electrical and electrochemical studies of core–shell structured nanorods of LiMn2O4@PANI composite

Polyaniline has received much concentration in both basic and applied studies because it has electrical and electrochemical properties comparable to those of both conventional semiconductors and metals. In this work, PANI was used as a conducting additive to formulate a nanocomposite as a high functioning cathode material for Li-ion batteries. PANI, spinel cathode materials of LiMn2O4, and LMO@PANI were synthesized and characterized via scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM of the composite illustrated the formation of long rods of LiMn2O4 covered by PANI layers. The electrical and electrochemical properties of the prepared materials were studied by electrochemical impedance spectroscopy as well as cyclic voltammetry. The composite sample showed higher electrical conductivity (5.5 × 10–2 S/cm) compared with that of PANI (9.1 × 10–4 S/cm) and also showed improving in its specific electrical capacity with a value of 75 mAh/g at a scan rate of 5 mV/s in 1 M LiNO3 electrolyte compared with that of PANI (33 mAh/g). The cycling stability of the composite electrode was significantly improved and showed cycling performance, with ~ 86.2% capacity retained over 1000 cycles. Results predict that the developed LMO@PANI nanocomposite could be used in an electrochemical energy storage device.