LiNi0.5Mn1.5O4 Research Articles

5V-class sulfurized spinel cathode stable in sulfide all-solid-state batteries

Sulfide all-solid-state lithium-ion batteries represent one of the most promising energy storage technologies duo to higher safety and ionic conductivities. To further improve its energy density and application, high-voltage LiNi0.5Mn1.5O4 (LNMO) spinel cathode is highly desirable due to its high energy density, low cost, environmental friendliness and Co-free nature. However, sulfide solid electrolyte is not compatible with LNMO cathode, for which issue the reported solutions majorly focus on surface coating. In this work, we propose an efficient approach to sulfurize LNMO itself for an essentially new LNMOS cathode, which not only suppresses interfacial side-reactions but also improve ionic/electronic conductivity of the cathode. This method ultimately improves the interfacial compatibility and consequently the LNMOS/sulfide all-solid-state-battery performances, including 3 times higher initial discharge capacity and much better reversible cycling stability. Detailed analyses on the interface are performed for in-depth understanding and further development of high-energy-density sulfide all-solid-state batteries using 5V-class spinel cathodes.

Long-life LiNi0.5Mn1.5O4/graphite lithium-ion cells with an artificial graphite-electrolyte interface

The high operating voltage of a spinel LiNi0.5Mn1.5O4 (LNMO) cathode leads to electrolyte decomposition and accelerated deterioration of the electrode/electrolyte interface in lithium-ion cells. Aggressive side reactions prevent long-term cycling and hinder its practical application. Advanced characterization shows that the high-voltage operation makes the graphite anode react with the electrolyte, particularly with the lithium salt in the electrolyte, resulting in massive active lithium inventory loss and capacity fade. The side reactions at the graphite are identified as the main culprit for the LNMO/graphite full cell decay. Here, we demonstrate that an artificial solid-electrolyte interface layer consisting of an ultra-thin Al2O3 film, generated via atomic layer deposition (ALD) at the graphite surface, can successfully isolate the graphite from the electrolyte and inhibit the undesired reactions. Consequently, the capacity and cycling stability of the LNMO/graphite cell are drastically improved. After 300 cycles, the capacity retention of LNMO/graphite cell increases from 57.7% to 98.6% with the ALD-coated graphite. Our findings provide valuable insights into the LNMO/graphite cell degradation and suggest a simple and robust, yet highly effective, approach for the practical viability of high-voltage lithium-ion batteries.

Structural, electrical and electrochemical characterization of hybrid morphological LiNi0.5Mn1.5O4 cathode material

Spinel LiNi0.5Mn1.5O4 (LNMO) cathode are effectively obtained by one-pot hydrothermal synthesis. Scanning electron microscopy (SEM) reveals the hybrid morphological of LNMO, featuring cotton-like structures (400–800 nm) and rod-like structures (90–150 nm). The equivalent circuit well describes the Nyquist plot to separate the grain and grain boundary effects. According to the Maxwell-Wagner model, the complex permittivity confirms non-homogenous layers' existence; highly conducting grains and poorly conducting grain boundaries. Non-overlapping polar tunneling (NSPT) and correlated barrier hopping (CBH) are two responsible models for the conduction mechanism at low and high temperatures. Further, identical activation energy values are observed for hopping frequency, and peak frequency from normalized parameters Z’’/Z’’ max and M’’/M’’ max, suggesting Li+ ions are the dominant charge carriers. The LNMO/Li cell delivers higher discharge capacity than commercial LNMO/Li cell from prior study, credits from the bridging features between rod-like and cotton-like particles.

Enhanced Electrochemical Performance of LiNi0.5Mn1.5O4 Composite Cathodes for Lithium-Ion Batteries by Selective Doping of K+/Cl- and K+/F.

K+/Cl− and K+/F− co-doped LiNi0.5Mn1.5O4 (LNMO) materials were successfully synthesized via a solid-state method. Structural characterization revealed that both K+/Cl− and K+/F− co-doping reduced the LixNi1−xO impurities and enlarged the lattice parameters compared to those of pure LNMO. Besides this, the K+/F− co-doping decreased the Mn3+ ion content, which could inhibit the Jahn–Teller distortion and was beneficial to the cycling performance. Furthermore, both the K+/Cl− and the K+/F− co-doping reduced the particle size and made the particles more uniform. The K+/Cl− co-doped particles possessed a similar octahedral structure to that of pure LNMO. In contrast, as the K+/F− co-doping amount increased, the crystal structure became a truncated octahedral shape. The Li+ diffusion coefficient calculated from the CV tests showed that both K+/Cl− and K+/F− co-doping facilitated Li+ diffusion in the LNMO. The impedance tests showed that the charge transfer resistances were reduced by the co-doping. These results indicated that both the K+/Cl− and the K+/F− co-doping stabilized the crystal structures, facilitated Li+ diffusion, modified the particle morphologies, and increased the electrochemical kinetics. Benefiting from the unique advantages of the co-doping, the K+/Cl− and K+/F− co-doped samples exhibited improved rate and cycling performances. The K+/Cl− co-doped Li0.97K0.03Ni0.5Mn1.5O3.97Cl0.03 (LNMO-KCl0.03) exhibited the best rate capability with discharge capacities of 116.1, 109.3, and 93.9 mAh g−1 at high C-rates of 5C, 7C, and 10C, respectively. Moreover, the K+/F− co-doped Li0.98K0.02Ni0.5Mn1.5O3.98F0.02 (LNMO-KF0.02) delivered excellent cycling stability, maintaining 85.8% of its initial discharge capacity after circulation for 500 cycles at 5C. Therefore, the K+/Cl− or K+/F− co-doping strategy proposed herein will play a significant role in the further construction of other high-voltage cathodes for high-energy LIBs.

Crystallographic-Site-Specific Structural Engineering Enables Extraordinary Electrochemical Performance of High-Voltage LiNi0.5 Mn1.5 O4 Spinel Cathodes for Lithium-Ion Batteries.

The development of reliable and safe high-energy-density lithium-ion batteries is hindered by the structural instability of cathode materials during cycling, arising as a result of detrimental phase transformations occurring at high operating voltages alongside the loss of active materials induced by transition metal dissolution. Originating from the fundamental structure/function relation of battery materials, the authors purposefully perform crystallographic-site-specific structural engineering on electrode material structure, using the high-voltage LiNi0.5 Mn1.5 O4 (LNMO) cathode as a representative, which directly addresses the root source of structural instability of the Fd m structure. By employing Sb as a dopant to modify the specific issue-involved 16c and 16d sites simultaneously, the authors successfully transform the detrimental two-phase reaction occurring at high-voltage into a preferential solid-solution reaction and significantly suppress the loss of Mn from the LNMO structure. The modified LNMO material delivers an impressive 99% of its theoretical specific capacity at 1 C, and maintains 87.6% and 72.4% of initial capacity after 1500 and 3000 cycles, respectively. The issue-tracing site-specific structural tailoring demonstrated for this material will facilitate the rapid development of high-energy-density materials for lithium-ion batteries.

In situ Sr2+-doped spinel LiNi0.5Mn1.5O4 cathode material for Li-ion batteries with high electrochemical performance and its impact on morphology

LiNi0.5Mn1.5O4 (LNMO) is a promising next-generation cathode material for high energy density lithium-ion batteries, but the application of LNMO is blocked because of its inherent side effects with electrolytes at high voltages, namely, serious Mn dissolution and capacity attenuation. A novel LiNi0.5Mn1.5-xSrxO4 material (x = 0, 0.05, 0.1, 0.15, and 0.2) was successfully prepared using the sol-gel method, and the effect of varying in situ Sr2+-doping on the crystal structure, morphology, and electrochemical performance was researched. A series of characterizations showed that the Sr-doped LNMO structure contains less Mn3+, which enhances its cycling stability. In addition, Sr doping promotes morphological changes more remarkably. Accompanied by the appearance of (100) surfaces, the morphology of LNMO changes from an octahedron to a truncated octahedron. The (100) surface can effectively inhibit side reactions with the electrolyte and steady the structure at the working voltage, which also helps support Li+ transport kinetics. The Sr-doped LiNi0.5Mn1.4Sr0.1O4 (expressed as LNMO-Sr0.1) cathode exhibits preeminent cycling stability, after 500 cycles at 1C, the capacity retention is 86.63 %. CV and EIS results show that the right amount of Sr doping efficiently reduces electrode polarization and charge transfer resistance and increases the Li+ diffusion coefficient.

High Voltage-Stabilized Graphdiyne Cathode Interface.

Suppressing the irreversible interfacial reactions is an important scientific bottleneck in the development of stable high-energy-density lithium-ion battery. The interfacial chemistry of graphdiyne (GDY) on the high-voltage cathode of LiNi0.5 Mn1.5 O4 (LNMO) shows a very interesting process, in which the sp-hybridization carbon atoms chemically scavenge the hydrofluoric acid (HF) and in situ form the fluorinated GDY interface. It first turns the harmful HF into profit, and greatly enhances the interfacial stability and restrains the side reaction on the cathode under high working voltage. The GDY-coated LNMO cathode obviously alleviates the electrolyte degradation, achieves high Coulombic efficiency and reliability. Due to atomic-level selectivity and chemical trapping of HF by GDY, it effectively suppresses the dissolution of Mn, Ni elements. These results highlight the unparalleled advantages of GDY in the formation of high stable interfaces and protection of high-energy-density electrodes.

In-situ XRD study of a Chromium doped LiNi0.5Mn1.5O4 cathode for Li-ion battery

This paper deals with structural (in-situ XRD) and electrochemical characterization of high-voltage lithium-ion cathode materials LiMn2O4 (LMO), LiNi0.5Mn1.5O4 (LNMO), and LiCr0.1Ni0.4Mn1.5O4 (LCNMO) prepared by solid-state synthesis. Structural in-situ X-ray diffraction spectra were measured by an affordable Rigaku diffractometer. Our synthesis route produced the samples with similar morphologies where the average particle sizes were 1.11 µm and 1.46 µm for LNMO and LCNMO respectively. Results of the Rietveld analysis brought detailed insight into two-phase structure transitions for LMO and three-phase transitions for LNMO and LCNMO. XRD study revealed differences in the structural behavior of LMO and LNMO prepared by solid-state synthesis compared to the results of other authors using the sol-gel synthesis route. In the case of chromium-doped LNMO, our results indicate ability of the chromium metal to effectively reduce Mn3+ content while the ordering of the structure increases. Chromium doping also promotes a larger lattice parameter in a fully delithiated state than in the case of undoped LNMO. Therefore, lowering of the volume changes was observed and faster phase II/III transition taking place, when Ni3+/Ni4+ redox pair was oxidized, was also identified. Cr doping of LNMO also promotes the reaching the lattice parameters of phases in both phase transitions and thus could reduce the internal stress of active material under high C-rate cycling. Results thus suggested that chromium doping can improve the stability of the inner structure and performance at higher charging C-rates even though the structure goes through a three-phase region during charging as undoped LNMO. The evaluation of diffusion coefficients of Cr-doped LNMO revealed increased diffusivity in a full discharge state and as the cathode underwent the cycling the differences in diffusivity seemed to be more pronounced.

RETRACTED: Hydrothermal MgF2 surface treatment of LiNi0.5Mn1.5O4 high voltage cathode materials for lithium-ion batteries

The LiNi0.5Mn1.5O4 cathode material is one of the popular electrode materials for research in the field of full cell operating at high voltage over 4.9 ​V. With increasing the high voltage, the spinel LiNi0.5Mn1.5O4 (LNMO) suffers from irreversible capacity fading during cycling and limited cycle life. In this work, it is shown the MgF2 surface modification of the LiNi0.5Mn1.5O4 cathode material via a facile hydrothermal method with an additional heat treatment step. The effect of MgF2 coating amount on the electrochemical cycling behavior of the LiNi0.5Mn1.5O4 electrode is investigated at the high upper voltage limit of 4.9 ​V. The cycling performance and rate capability of the LNMO electrode are related to the amount of MgF2 coating. The electrochemical performance of the MgF2-coated LNMO decreased with increasing MgF2 coating amount but showed enhanced properties, compared to the pristine material. The 1 ​wt% MgF2-coated LNMO have the best electrochemical performance, showing higher specific capacities and lower surface resistance after 150 cycles at various current densities. Obtained the electrochemical performance suggested that the MgF2 thin coating layer (1 ​wt%) obtained via the hydrothermal method plays an important role in stabilizing the positive electrode/electrolyte interface and the host structure, and can prevent the formation of side reaction components and improve lithium-ion diffusion resulting in the stabilization of cathode surface compared to the pristine material.

Modification of aluminum current collectors with laser-scribed graphene for enhancing the performance of lithium ion batteries

In this study, the graphene-modified Al foils are prepared to assemble lithium ion batteries (LIBs) through a three-step approach comprising: (1) deposition of the polyamic acid (PAA) on the Al substrate; (2) curing the PAA to form the polyimide (PI)-coated Al foils; (3) converting the PI into porous graphene by CO2 laser irradiation. With integration of the PI derived graphene (PDG) in the LIBs, the inserted PDG layer can enhance the adhesion and interface resistance between the active layer and Al electrode. The LiNi0.5Mn1.5O4 (LNMO)//Li4Ti5O12 (LTO) full cells with PDG layer are also fabricated to evaluate the effect of the modified layer on the cell performance. Compared to the pristine Al electrode, the modified current collector can improve the rate performance and reduce the temperature rise during the charge/discharge process leading to better cycling stability.

Toward High Performance All‐Solid‐State Lithium Batteries with High‐Voltage Cathode Materials: Design Strategies for Solid Electrolytes, Cathode Interfaces, and Composite Electrodes

AbstractAll‐solid‐state lithium batteries (ASSLBs) with nonflammable solid electrolytes (SEs) deliver greatly enhanced safety characteristics. Furthermore, ASSLBs composed of cathodes with high working voltages, such as LiCoO2, LiNixCoyMnzO2 (x + y + z = 1, NCM), LiNixCoyAlzO2 (x + y + z = 1, NCA), LiMnxFeyPO4 (x + y = 1, LMFP), and LiNi0.5Mn1.5O4 (LNMO), and a lithium metal anode can achieve comparable or better performance compared with that of LLBs in terms of energy density. Therefore, high‐voltage ASSLBs have been regarded as the most promising next‐generation batteries. Although significant progress has been achieved in high‐voltage ASSLBs research, their development still faces multiple challenges. To facilitate further effective and target‐oriented research on high‐voltage ASSLBs, a summary of recent research progress is urgently needed. In this review, recent research progress in high‐voltage ASSLBs is summarized from the perspectives of SEs modification, interfacial challenges and their corresponding solutions for cathodes, and high‐voltage composite cathode design for practical applications. Finally, the authors’ perspectives on the state of current ASSLBs research, aiming to propose possible research directions for the future development of high‐voltage ASSLBs.

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.

Tuning the phase evolution pathway of LiNi0.5Mn1.5O4 synthesis from binary intermediates to ternary intermediates with thermal regulating agent

Transition metal cation ordering is essential for controlling the electrochemical performance of cubic spinel LiNi0.5Mn1.5O4 (LNMO), which is conventionally adjusted by optimizing the high temperature sintering and annealing procedures. In this present work, multiple characterization techniques, including 6,7Li NMR, XRD and HRTEM, have been combined to trace the phase transformation and morphology evolution during synthesis. It has been illustrated that simultaneous formation of LiMn2O4 (LMO) and LiNiO2 (LNO) binary oxides and their conversion into highly reactive LixNi3+yMn3.5+zO ternary intermediate is a thermal dynamically difficult but crucial step in the synthesis of LNMO ternary oxide. A new strategy of modifying the intermediates formation pathway from binary mode to ternary mode using thermal regulating agent has been adopted. LNMO synthesized with thermal regulating agent exhibits supreme rate capability, long-cycling performance (even at elevated temperature) and excellent capacity efficiency. At a high rate of 100 C, the assembled battery delivers a discharge capacity of 99 mAh g−1. This study provides a way to control the formation pathway of complex oxides using thermal regulating agent.

Fast and Scalable Synthesis of LiNi0.5Mn1.5O4 Cathode by Sol–Gel‐Assisted Microwave Sintering

High‐voltage spinel LiNi0.5Mn1.5O4 (LNMO) is a promising cathode material for high‐energy‐density and high‐power‐density lithium‐ion batteries (LIBs). The high cost of the currently available LIBs needs to be addressed urgently for wide application in the transport sector (electric vehicles, buses) and large‐scale energy storage systems (ESS). Of significance, herein, novel fast and scalable microwave‐assisted synthesis of LNMO is reported, which leads to a production cost cut. X‐ray diffraction (XRD) analysis confirms the formation of the desired phase with high crystallinity. Field emission scanning (FE‐SEM) and transmission electron microscopy (TEM) analyses indicate that the synthesized phase is of nanometric size (50–150 nm) due to an extremely short sintering time (20 min). The material synthesized at 750 °C shows a higher initial discharge capacity (130 mA h g−1) than that synthesized at 650 °C (115 mA h g−1). The materials heat treated at higher temperatures show better electrochemical performance in terms of initial capacity, rate capability, and improved cycling. The improved electrochemical performance of LNMO at 750 °C is attributed to the formation of a stable crystal structure, low charge transfer resistance at the electrode/electrolyte interface, high electrical conductivity due to the presence of a disorder structure, and improved ionic diffusivity.

Insight into wide temperature electrolyte based on lithiumdifluoro(oxalate)borate for high voltage lithium-ion batteries

Spinel LiNi0.5Mn1.5O4 (LNMO) cathode with high voltage plateau at around 4.7 V (vs. Li/Li+) has attracted great attention. However, the lack of suitable electrolyte hinders its application. Although lithium difluoro(oxalate)borate (LiODFB)-based electrolyte has been proved to be suitable for high voltage electrolyte, traditional LiODFB-based electrolyte has poor low and high temperature performance. Therefore, we confirm that lithium difluorophosphate (LiPO2F2, LiDFP) as LiODFB-based electrolyte additive and dimethyl sulfite (DMS) as co-solvent significantly improve electrochemical performance of LNMO/Graphite full batteries at low and high temperature. Various physical and electrochemical techniques are used to investigate the effect of four electrolytes. The effect on cathode is mainly attributed to priority oxidation decomposition of LiDFP. The formed interface film can inhibit the dissolution of Mn2+, thereby improving the high temperature electrochemical performance. The effect on anode is that the interface film formed by LiODFB prevents continuous reduction of solvents and additive. The enhanced low temperature performance is due to the significantly increased ionic conductivity of DMS-containing electrolytes at low temperature. Besides, the formed of the cathode electrolyte interphase (CEI) membrane with low impedance by LiDFP can improve the kinetics of cathode/electrolyte interface, therefore enhancing the low and high temperature performance of LNMO/Graphite full cells.

Instantaneous Surface Li3PO4 Coating and Al–Ti Doping and Their Effect on the Performance of LiNi0.5Mn1.5O4 Cathode Materials

Using hydrogen peroxide (H2O2), a novel approach was applied for the synthesis of LiNi0.5Mn1.5O4 (LNMO) coated with Li3PO4 and doped with Al3+ and Ti4+ ions. The reaction between LNMO and H2O2 resulted in particles with a partially damaged surface. If the same reaction is done in the presence of lithium, aluminum, titanium, and phosphate ingredients, then all particle facets are intact and show no sign of destruction. It appears that the H2O2 decomposition activates the LNMO surface, generating perfect conditions for the homogeneous deposition of the Li, Al, Ti, and phosphate ions. Electrochemical investigations show a very slow fading process during the cycling, and even after more than 500 cycles, the obtained cathode material shows a high specific capacity of 127 mAh g–1 (at 1 C) (∼98% capacity retention) and an excellent Coulombic efficiency (99.5%).

Atomic Layer Deposition of a Nanometer-Thick Li3PO4 Protective Layer on LiNi0.5Mn1.5O4 Films: Dream or Reality for Long-Term Cycling?

LiNi0.5Mn1.5O4 (LNMO) is a promising 5V-class electrode for Li-ion batteries but suffers from manganese dissolution and electrolyte decomposition owing to the high working potential. An attractive solution to stabilize the surface chemistry consists in mastering the interface between the LNMO electrode and the liquid electrolyte with a surface protective layer made from the powerful surface deposition method. Here, we show that a 7400 nm thick sputtered LNMO film coated with a nanometer-thick lithium-ion-conductive Li3PO4 layer was deposited by the atomic layer deposition method. We demonstrate that this "material model system" can deliver a remarkable surface capacity (∼0.4 mAh cm-2 at 1C) and exhibits improved cycling lifetime (×650%) compared to the nonprotected electrode. Nevertheless, we observe that mechanical failure occurs within the LNMO and Li3PO4 films when long-term cycling is performed. This in-depth study gives new insights regarding the mechanical degradation of LNMO electrodes upon charge/discharge cycling and reveals for the first time that the surface protective layer made from the ALD method is not sufficient for long-term stability applications.

Tackling the Interfacial Issues of Spinel LiNi0.5Mn1.5O4 by Room-Temperature Spontaneous Dediazonation Reaction.

The detrimental interfacial side reactions, inducing electrolyte decomposition and transition-metal dissolution, are regarded as "arch-criminal" for the utilization of spinel LiNi0.5Mn1.5O4 (LNMO) in high-power Li-ion batteries (LIBs). To conquer this issue, herein, we construct a thin polyphenyl film onto the surface of LNMO via the spontaneous dediazonation of C6H5N2+BF4- at room temperature. This conductive film facilitates the Li+ transport within cathode and at LNMO|electrolyte interface while reinforcing the compatibility of LNMO against electrolyte by efficiently suppressing the electrolyte decomposition catalyzed by LNMO and even the transition-metal dissolution. Consequently, polyphenyl-grafted LNMO exhibits improved electrochemical performances, e.g., the considerable discharge capacity of 136.7 mAh g-1 at low current density (0.1C), excellent rate capability, and long-term cyclability with a reversible capacity of 107.4 mAh g-1 along with high capacity retention of ∼85% after cycling 500 times, that are superior to those of the pristine LNMO counterpart. All these results demonstrate that our strategy is instrumental in solving the interface issues with respect to the spinel LNMO cathode, impelling the development of LNMO-based batteries with high energy density.

Study on Thermal Simulation of LiNi0.5Mn1.5O4/Li4Ti5O12 Battery

A thermal simulation model is developed to analyze the thermal behavior of the lithium‐ion battery. This model precisely considers the thermal properties of battery materials, including cathode, anode, and electrolyte. The LiNi0.5Mn1.5O4 (LNMO)/Li4Ti5O12 (LTO) battery is modeled for the first time, and the accuracy is verified by an experimental battery test. The results demonstrate that the thermal runaway of the battery is mainly caused by the decomposition of LNMO. Little heat absorbed by the gasification of electrolyte solvent and highly thermal stable LTO account for a relatively small proportion of the factors leading to the battery temperature rise. The similar results of simulation and accelerating rate calorimeter (ARC) testing under the adiabatic condition indicate that the thermal simulation model utilized in this work is a good guidance for safety design of the LNMO/LTO battery.

Composition manipulation of bis(fluorosulfonyl)imide-based ionic liquid electrolyte for high-voltage graphite//LiNi0.5Mn1.5O4 lithium-ion batteries

Ionic liquids (ILs), with wide electrochemical stability window, high thermal stability, and nonvolatility, are promising electrolytes for lithium-ion batteries. Among ILs with various types of anion, bis(fluorosulfonyl)imide (FSI−)-based ILs are particularly appealing owing to their high ionic conductivity, low viscosity, and great anode compatibility. However, strong corrosivity of FSI− toward the Al current collector at high potential restricts their practical utilization. In this study, three strategies are implemented to overcome this limitation. Li+ fraction modulation, FSI−/bis(trifluoromethyl)sulfonylimide (TFSI−) molar ratio optimization, and their synergistic combination are used to achieve optimal charge–discharge of a high-voltage LiNi0.5Mn1.5O4 (LNMO) cathode with an Al substrate. The effects of the IL composition on the electrochemical properties of a graphite anode are also investigated. The proposed IL electrolyte, which lacks any organic solvents, has an optimal Li+/FSI−/TFSI− molar ratio and thus can effectively suppress the Al corrosion, allowing a 5-V graphite//LNMO full cell to be realized. A reversible capacity of ~ 135 mAh g−1 (based on LNMO) and a capacity retention of ~ 85% after 200 cycles are found for the full cell. This study opens a new route for FSI−-based IL electrolytes in the field of high-voltage and high-safety lithium-ion battery applications.