Investigation on lithium ion conductivity and structural stability of yttrium-substituted Li<Subscript>7</Subscript>La<Subscript>3</Subscript>Zr<Subscript>2</Subscript>O<Subscript>12</Subscript>

Advanced Li-air battery architecture demands a high Li⁺ conductive solid electrolyte membrane that is electrochemically stable against metallic lithium and aqueous electrolyte. In this work, an investigation has been carried out on the microstructure, Li⁺ conduction behaviour and structural stability of Li₇La_3-x Y _x Zr₂O₁₂ (x = 0.125, 0.25 and 0.50) prepared by conventional solid-state reaction technique. The phase analysis of Li₇La_3-x Y _x Zr₂O₁₂ (x = 0.125, 0.25 and 0.50) sintered at 1200 °C by powder X-ray diffraction (PXRD) and Raman confirms the formation of high Li⁺ conductive cubic phase (\( Ia\overline{3}d \)) lithium garnets. Among the investigated lithium garnets, Li₇La_2.75Y_0.25Zr₂O₁₂ sintered at 1200 °C exhibits a maximized room temperature total (bulk + grain boundary) Li⁺ conductivity of 3.21 × 10^?4 S cm^?1 along with improved relative density of 96 %. The preliminary investigation on the structural stability of Li₇La_2.75Y_0.25Zr₂O₁₂ in the solutions of 1 M LiCl, dist. H₂O and 1 M LiOH at 30 °C/50 °C indicates that the Li₇La_2.75Y_0.25Zr₂O₁₂ is relatively stable against 1 M LiCl and dist. H₂O. Further electrochemical investigation is essential for practical application of Li₇La_2.75Y_0.25Zr₂O₁₂ as protective solid electrolyte membrane in aqueous Li-air battery.     

Comparative study of solid-state reaction and sol-gel process for synthesis of Zr-doped Li<Subscript>0.5</Subscript>La<Subscript>0.5</Subscript>TiO<Subscript>3</Subscript> solid electrolytes

We investigated the synergistic influences of synthesis methods (solid-state reaction vs. sol-gel process) and Zr⁴⁺ doping on the structure and ionic conductivity of perovskite-structured Li_0.5La_0.5TiO₃ (LLTO) solid electrolytes. The lithium-ion conductivity of Li_0.5La_0.5Ti_1???x Zr _x O₃ ceramic specimens was evaluated as a function of x value and compared carefully between those two synthesis methods. Regarding the conductivity, sol-gel process is better for the synthesis of LLTO than solid-state reaction. As a result, the highest grain conductivity is obtained in the sol-gel-derived pure LLTO sample with x?=?0, reaching 1.10?×?10^?3 S?·?cm^?1. Partial substitution of Zr⁴⁺ enlarges the LLTO’s grain aggregate size and increases the total superficial area of aggregates. Consequently, Zr⁴⁺ substitution not only affects the grain (bulk) conductivity, but more importantly, also improves the grain boundary conductivity and the total conductivity. The highest total conductivity is 5.84?×?10^?5 S?·?cm^?1 with x?=?0.04 by sol-gel process.     

Low-temperature sintering effects on NASICON-structured LiSn<Subscript>2</Subscript>P<Subscript>3</Subscript>O<Subscript>12</Subscript> solid electrolytes prepared via citric acid-assisted sol-gel method

LiSn₂P₃O₁₂ with sodium (Na) super ionic conductor (NASICON)-type rhombohedral structure was successfully obtained at low sintering temperature, 600 °C via citric acid-assisted sol-gel method. However, when the sintering temperature increased to 650 °C, triclinic structure coexisted with the rhombohedral structure as confirmed by X-ray diffraction analysis. Conductivity–temperature dependence of all samples were studied using impedance spectroscopy in the temperature range 30 to 500 °C, and bulk, grain boundary and total conductivity increased as the temperature increased. The highest bulk conductivity found was 3.64?×?10^?5 S/cm at 500 °C for LiSn₂P₃O₁₂ sample sintered at 650 °C, and the lowest bulk activation energy at low temperature was 0.008 eV, showing that sintering temperature affect the conductivity value. The voltage stability window for LiSn₂P₃O₁₂ sample sintered at 600 °C at ambient temperature was up to 4.4 V. These results indicated the suitability of the LiSn₂P₃O₁₂ to be exploiting further for potential applications as solid electrolytes in electrochemical devices.     

Studies on structural and electrical properties of Mg<Subscript>0. 5+y</Subscript> (Zr<Subscript>2-y</Subscript>Fe<Subscript>y</Subscript>) <Subscript>2</Subscript> (PO<Subscript>4</Subscript>) <Subscript>3</Subscript> ceramic electrolytes

The sample of Mg_{0. 5+y} (Zr_1-y Fe_y) ₂ (PO₄) ₃ (0.0 ≤y ≤0.5) was synthesized using the sol-gel method. The structures of the samples were investigated using X-ray diffraction and Fourier transform infrared spectroscopy measurement. XRD studies showed that samples had a monoclinic structure which was iso-structured with the parent compound, Mg_0.5Zr (PO₄) ₃. The complex impedance spectroscopy was carried out in the frequency range 1–6 MHz and temperature range 303 to 773 K to study the electrical properties of the electrolytes. The substitutions of Fe³⁺ with Zr⁴⁺ in the Mg_0.5Zr (PO₄) ₃ structure was introduced as an extrainterstitial Mg²⁺ ion in the modified structured. The compound of Mg_0.5+y (Zr_1-y Fe_y)₂(PO₄)₃ with y?=?0.4 gives a maximum conductivity value of 1.25?×?10^?5 S cm^?1 at room temperature and 7.18?×?10^?5 S cm^?1 at 773 K. Charge carrier concentration, mobile ion concentration, and ion hopping rate are calculated by fitting the conductance spectra to power law variation, σ _ac (ω)?=?σ _o ? +?Aω ^α . The charge carrier concentration and mobile ion concentration increases with increase of Fe³⁺ inclusion. This implies the increase in conductivity of the compounds was due to extra interstitial Mg²⁺ ions.     

Fast ionic conduction in cubic hafnium garnet Li<Subscript>7</Subscript>La<Subscript>3</Subscript>Hf<Subscript>2</Subscript>O<Subscript>12</Subscript>

A new member of the family of garnets with fast lithium ion conduction has been found with the composition Li₇La₃Hf₂O₁₂. The anion arrangement corresponds to the oxygen framework in garnets, e.g., in Ca₃Fe₂Si₃O₁₂. Hafnium is coordinated octahedrally while the lanthanum environment can be described as a distorted cube. Lithium occupies a large number of positions with tetrahedral, trigonal planar, and metaprismatic coordination. Li₇La₃Hf₂O₁₂ shows a lithium bulk ion conductivity of 2.4 × 10⁻⁴ Ω⁻¹ cm⁻¹ at room temperature with an activation energy of 0.29 eV.     

Investigation of ion transport in Li<Subscript>8</Subscript>ZrO<Subscript>6</Subscript> and Li<Subscript>6</Subscript>Zr<Subscript>2</Subscript>O<Subscript>7</Subscript> solid electrolytes

Lithium ionic conductivity and spin-lattice relaxation rates were measured in Li₈ZrO₆ and Li₆Zr₂O₇ solid electrolytes. It was found that the Li₈ZrO₆ solid electrolyte undergoes a transition to the superionic state in the temperature range 673–703 K. It was shown that Li⁺ ions are mobile in particular lattice positions of the Li₆Zr₂O₇ phase, and that ionic conductivity is monotonic at an activation energy of 79.4 kJ/mol.     

Genesis,structural, and transport properties of La<Subscript>2</Subscript>Mo<Subscript>2-x</Subscript>W<Subscript>x</Subscript>O<Subscript>9</Subscript> prepared via mechanochemical activation

Fast oxide-ion conductors La₂Mo_2-xW_xO₉ (x = 0–1) have been prepared using mechanochemical activation (MA) of starting oxides in a high-power planetary ball mill. Studies of La₂Mo_2-xW_xO₉ genesis and structural properties using thermal analysis, XRD, SEM, IR, and Raman spectroscopy have revealed that MA results in the formation of an amorphous precursor, while the cubic β-phase is formed after calcination at 700–900 °C. Due to a high dispersion of powders, high-density pellets of W-LAMOX ceramics have been obtained already after sintering at 950 °C. Their electrical conductivity measured by the impedance spectroscopy depends on the W concentration being sufficiently high (up to 5.6?10^?3 S/cm at 630 °C) at temperatures below 650 °C.     

Titanium-modified Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> with a synergistic effect of surface modifying,bulk doping,and size reducing

In this work, a one-step solid-phase sintering process via TiO₂ and Li₂CO₃ under an argon atmosphere, with ultra-fine titanium powder as the modifying agent, was used to prepare a nano-sized Li₄Ti₅O₁₂/Ti composite (denoted as LTO–Ti) at 800 °C. The introduction of ultra-fine metal titanium powder played an important role. First, X-ray photoelectron spectroscopy demonstrates that Ti⁴⁺ was partially changed into Ti³⁺, through the reduction of the ultra-fine metal titanium powder. Second, X-ray diffraction revealed that the ultra-fine metal titanium powder did not react with the bulk structure of Li₄Ti₅O₁₂, while some pure titanium peaks could be seen. Additionally, the size of LTO–Ti particles could be significantly reduced from micro-scale to nano-scale. The structure and morphology of LTO–Ti were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. Electrochemical tests showed a charge/discharge current of 0.5, 1, 5, and 10 C; the discharge capacity of the LTO–Ti electrode was 170, 161, 140, and 111 mAh g^?1. It is believed that the designed LTO–Ti composite makes full use of both components, thus offering a large contact area between the electrolyte and electrode, high electrical conductivity, and lithium-ion diffusion coefficient during electrochemical processes. Furthermore, ultra-fine titanium powder, as the modifying agent, is amenable to large-scale production.     

Pr-modified Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> nanofibers as an anode material for lithium-ion batteries with outstanding cycling performance and rate performance

Pr-doped Li₄Ti₅O₁₂ in the form of Li_4?x/3Ti_5?2x/3Pr_xO₁₂ (x = 0, 0.01, 0.03, 0.05, and 0.07) was synthesized successfully by an electrospinning technique. ICP shows that the doped samples are closed to the targeted samples. XRD analysis demonstrates that traces of Pr³⁺ can enlarge the lattice parameter of Li₄Ti₅O₁₂ from 8.3403 to 8.3765 Å without changing the spinel structure. The increase of lattice parameter is beneficial to the intercalation and de-intercalation of lithium-ion. XPS results identify the existence form of Ti is mainly Ti⁴⁺ and Ti³⁺ in minor quantity in Li_4?x/3Ti_5?2x/3Pr_xO₁₂ (x = 0.05) samples due to the small amount of Pr³⁺. The transition from Ti⁴⁺ to Ti³⁺ is conducive to the electronic conductivity of Li₄Ti₅O₁₂. FESEM images show that all the nanofibers are well crystallized with a diameter of about 200 nm and distributed uniformly. The results of electrochemical measurement reveal that the 1D Li_4?x/3Ti_5?2x/3Pr_xO₁₂ (x = 0.05) nanofibers display enhanced high-rate capability and cycling stability compared with that of undoped nanofibers. The high-rate discharge capacity of the Li_4?x/3Ti_5?2x/3Pr_xO₁₂ (x = 0.05) samples is excellent (101.6 mAh g^?1 at 50 °C), which is about 58.48 % of the discharge capacity at 0.2 °C and 4.3 times than that of the bare Li₄Ti₅O₁₂ (23.5 mA g^?1). Even at 10 °C (1750 mA g^?1), the specific discharge capacity is still 112.8 mAh g^?1 after 1000 cycles (87.9 % of the initial discharge capacity). The results of cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS) illustrate that the Pr-doped Li₄Ti₅O₁₂ electrodes possess better dynamic performance than the pure Li₄Ti₅O₁₂, further confirming the excellent electrochemical properties above.     

Nano Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> as sulfur host for high-performance Li-S battery

S/Li₄Ti₅O₁₂ cathode with high lithium ionic conductivity was prepared for Li-S battery. Herein, nano Li₄Ti₅O₁₂ is used as sulfur host and fast Li⁺ conductor, which can adsorb effectively polysulfides and improve remarkably Li⁺ diffusion coefficient in sulfur cathode. At 0.5 C, S/Li₄Ti₅O₁₂ cathode has a stable discharge capacity of 616 mAh g^?1 at the 700th cycle and a capacity loss per cycle of 0.0196% from the second to the 700th cycle, but the corresponding values of S/C cathode are 437 mAh g^?1 and 0.0598%. Even at 2 C, the capacity loss per cycle of S/Li₄Ti₅O₁₂ cathode is only 0.0273% from the second to the 700th cycle. The results indicate that Li₄Ti₅O₁₂ as the sulfur host plays a key role on the high performance of Li-S battery due to reducing the shuttle effect and enhancing lithium ionic conductivity.     

Effect of sintering conditions on the properties of sol-gel-derived Li<Subscript>1.3</Subscript>Al<Subscript>0.3</Subscript>Ti<Subscript>1.7</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript>

Solid electrolyte Li_1.3Al_0.3Ti_1.7(PO₄)₃ was prepared by sol-gel method under different sintering conditions. The structural identification, surface morphology, electrochemical window, ionic conductivity, and activation energy of the Li_1.3Al_0.3Ti_1.7(PO₄)₃ sintered pellets were investigated by X-ray diffraction, scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. It is found that the sintering temperature and time have considerable effect on the properties of the Li_1.3Al_0.3Ti_1.7(PO₄)₃ sintered pellets. The Li_1.3Al_0.3Ti_1.7(PO₄)₃ pellet sintered at 900 °C for 2 h is denser than the pellets sintered at other conditions. Different sintering conditions result in the sintered pellet with different porosity. However, the sintering conditions have little effect on the electrochemical window of Li_1.3Al_0.3Ti_1.7(PO₄)₃. Among the Li_1.3Al_0.3Ti_1.7(PO₄)₃ pellets sintered at various conditions, the pellet sintered at 900 °C for 2 h shows the highest ionic conductivity of 3.46 × 10⁻⁴ S cm⁻¹ and the lowest activation energy of 0.2821 eV.     

The all-solid-state battery with vanadate glass-ceramic cathode

The Ga-Ag-Li|Li₇La₃Zr_1.89Al_0.15O₁₂|(Li₂O–B₂O₃–V₂O₅ + Fe) all-solid-state electrochemical cell has been designed with a simple sintering process. The Li₇La₃Zr_1.89Al_0.15O₁₂ solid electrolyte was prepared by sol-gel method. The lithium borovanadate glass was obtained by a convenient melt quenching technique. Cycliс voltammetry has shown that the current densities of the cell at 300 °C can reach several hundreds of μA cm^?2. At this temperature, the single cell voltage is about 3.2 and 0.8 V in the charged and discharged state, correspondingly. This cell produces a current enough to make a single LED of white color working. The cell surface discharge capacity exceeds 230 μAh cm^?2.     

Thermal properties and ionic conductivity of Li<Subscript>1,3</Subscript>Ti<Subscript>1,7</Subscript>Al<Subscript>0,3</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript> solid electrolytes sintered by field-assisted sintering

Li_1,3Ti_0,7Al_0,3(PO₄)₃ (LATP) powder was obtained by a conventional melt-quenching method and consolidated by field-assisted sintering technology (FAST) at different temperatures. Using this technique, the samples could be sintered to relative densities in the range of 93 to 99 % depending on the sintering conditions. Ionic and thermal conductivity were measured and the results are discussed under consideration of XRD and SEM analyses. Thermal conductivity values of 2 W/mK and ionic conductivities of 4?×?10^?4 Scm^?1 at room temperature were obtained using relatively large particles and a sintering temperature of 1000 °C at an applied uniaxial pressure of 50 MPa.     

Preparation and electrochemical properties of Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript>/Ti<Subscript>4</Subscript>O<Subscript>7</Subscript> composite for lithium-ion batteries

In order to improve the rate capability of Li₄Ti₅O₁₂, Ti₄O₇ powder was successfully fabricated by improved hydrogen reduction method, then a dual-phase composite Li₄Ti₅O₁₂/Ti₄O₇ has been synthesized as anode material for lithium-ion batteries. It is found that the Li₄Ti₅O₁₂/Ti₄O₇ composite shows higher reversible capacity and better rate capability compared to Li₄Ti₅O₁₂. According to the charge-discharge tests, the Li₄Ti₅O₁₂/Ti₄O₇ composite exhibits excellent rate capability of 172.3 mAh g^?1 at 0.2 C, which is close to the theoretical value of the spinel Li₄Ti₅O₁₂. More impressively, the reversible capacity of Li₄Ti₅O₁₂/Ti₄O₇ composite is 103.1 mAh g^?1 at the current density of 20 C after 100th cycles, and it maintains 84.8% of the initial discharge capacity, whereas that of the bare spinel Li₄Ti₅O₁₂ is only 22.3 mAh g^?1 with a capacity retention of 31.1%. The results indicate that Li₄Ti₅O₁₂/Ti₄O₇ composite could be a promising anode material with relative high capacity and good rate capability for lithium-ion batteries.     

Synthesis,characterization, and cell performance of Li<Subscript>0.5</Subscript>FeV<Subscript>1.5</Subscript>O<Subscript>4</Subscript>

A Li_0.5FeV_1.5O₄ sample was synthesized using sol-gel route. The X-ray diffraction study indicates formation of spinel phase (with Fd3m space group) for this sample. LiO₄, LiO₆, and V-O bonds were identified from the Raman spectrum, while LiO₄ and Fe-O bonds were identified from the FTIR spectrum of this sample phase. The FESEM study indicates formation of inhomogeneous grains. The surface area of 74.39 m²/g was estimated from the Brunauer-Emmett-Teller (BET) surface area analysis technique. The cyclic voltammetry study of Li_0.5FeV_1.5O₄ indicates an anodic peak at 2.1 V while a cathodic peak at 1.98 V. The charge-discharge study exhibits two voltage plateaus respectively at 2.1 and at 4 V. Stable electrochemical capacity of 40 mAh/g for Li_0.5FeV_1.5O₄ was found for 30 cycles. The electrochemical impedance spectroscopy study indicates smaller bulk resistance and higher ionic diffusion, i.e., less Warburg impedance for this phase. An energy density of 89 Wh/kg, a power density of 33 W/kg, and a 90% Coulombic efficiency was achieved with relatively good cyclic stability from Li_0.5FeV_1.5O₄.     

Enhanced electrochemical performance of Cu<Subscript>2</Subscript>O-modified Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> anode material for lithium-ion batteries

Li₄Ti₅O₁₂/Cu₂O composite was prepared by ball milling Li₄Ti₅O₁₂ and Cu₂O with further heat treatment. The structure and electrochemical performance of the composite were investigated via X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge tests. Li₄Ti₅O₁₂/Cu₂O composite exhibited much better rate capability and capacity performance than pristine Li₄Ti₅O₁₂. The discharge capacity of the composite at 2 C rate reached up to 122.4 mAh g^?1 after 300 cycles with capacity retention of 91.3 %, which was significantly higher than that of the pristine Li₄Ti₅O₁₂ (89.6 mAh g^?1). The improvement can be ascribed to the Cu₂O modification. In addition, Cu₂O modification plays an important role in reducing the total resistance of the cell, which has been demonstrated by the electrochemical impedance spectroscopy analysis.     

Dramatic reduction in the densification temperature of garnet-type solid electrolytes

Cubic garnet Li₇La₃Zr₂O₁₂ (LLZO) and similar compositions of fast ion-conducting solid-state electrolytes have shown great potential for the development of high-energy-density solid-state Li-ion batteries. Although these materials have shown unprecedented ionic conductivities and chemical stability, these materials require high processing temperatures for synthesis. For many of the common compositions of LLZO, temperatures above 1000 °C are required to form the cubic garnet phase and to achieve high conductivities. Therefore, lowering the processing temperatures of these materials is of great interest for the purposes of scalability and fabrication. It has been reported that a Bi co-dopant not only stabilizes the cubic garnet phase but also lowers the densification temperature. In this study, Li₆La₃ZrBiO₁₂ (LLZBO) was prepared by a rapid-induction hot-pressing technique and characterized using a variety of techniques, including X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. We demonstrate the ability to synthesize phase-pure LLZBO with higher relative densities (~?94%) than can be achieved by pressure-less sintering methods, at pressing temperatures of only 850 °C. The ionic conductivity was measured to be 0.1 mS cm^?1, which is comparable to the best reported conductivities of high-density LLZO. This demonstrates the ability to fabricate dense, phase-pure, and high-conductivity LLZBO at temperatures significantly lower than other garnet compositions, which will prove useful for scalability and reducing reactivity with cathodes during densification.     

Conductivity and spectroscopic studies of Li<Subscript>2</Subscript>O-V<Subscript>2</Subscript>O<Subscript>5</Subscript>-B<Subscript>2</Subscript>O<Subscript>3</Subscript> glasses

Lithium vanadium-borate glasses with the composition of 0.3Li₂O–(0.7-x)B₂O₃–xV₂O₅ (x?=?0.3, 0.325, 0.35, 0.375, 0.4, 0.425, 0.45, and 0.475) were prepared by melt-quenching method. According to differential scanning calorimetry data, vanadium oxide acts as both glass former and glass modifier, since the thermal stability of glasses decreases with an increase in V₂O₅ concentration. Fourier transform infrared spectroscopy data show that the vibrations of [VO₄] structural units occur at V₂O₅ concentration of 45 mol%. It is established that the concentration of V⁴⁺ ions increases exponentially with the growth of vanadium oxide concentration. Direct and alternative current measurements are carried out to estimate the contribution both electronic and ionic conductivities to the value of total conductivity. It is shown that the electronic conductivity is predominant in the total one. The glass having the composition of 0.3Li₂O-0.275B₂O₃-0.475V₂O₅ shows the highest electrical conductivity that has the value of 7.4?×?10^?5 S cm^?1 at room temperature.     

Electrospinning preparation of one-dimensional Co<Superscript>2+</Superscript>-doped Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> nanofibers for high-performance lithium ion battery

One-dimensional Co²⁺-doped Li₄Ti₅O₁₂ nanofibers with a diameter of approximately 500 nm have been synthesized via a one-step controllable electrospinning method. The Co²⁺-doped Li₄Ti₅O₁₂ nanofibers were systematically characterized by XRD, ICP, TEM, SEM, BET, EDS mapping, and XPS. Based on the cubic spinel structure and one-dimensional effect of Li₄Ti₅O₁₂, Co²⁺-doped Li₄Ti₅O₁₂ nanofibers exhibit the enlarged lattice volume, reduced particle size and enhanced electrical conductivity. More importantly, Co²⁺-doped Li₄Ti₅O₁₂ nanofibers as a lithium ion battery anode electrode performs superior electrochemical performance than undoped Li₄Ti₅O₁₂ electrode in terms of electrochemical measurements. Particularly, the reversible capacity of Co²⁺-doped Li₄Ti₅O₁₂ electrode reaches up to 140.1 mAh g^?1 and still maintains 136.5 mAh g^?1 after 200 cycles at a current rate of 5 C. Therefore, one-dimensional Co²⁺-doped Li₄Ti₅O₁₂ nanofiber electrodes, showing high reversible capacity and remarkable recycling property, could be a potential candidate as an anode material.     

Investigation on the electrochemical performances of Li<Subscript>4</Subscript>Mn<Subscript>5</Subscript>O<Subscript>12</Subscript> for battery applications

In this study, well-crystallized Li₄Mn₅O₁₂ powder was synthesized by a self-propagating combustion method using citric acid as a reducing agent. Various conditions were studied in order to find the optimal conditions for the synthesis of pure Li₄Mn₅O₁₂. The precursor obtained was then annealed at different temperatures for 24 h in a furnace. X-ray diffraction results showed that Li₄Mn₅O₁₂ crystallite is stable at relatively low temperature of 400 °C but decompose to spinel LiMn₂O₄ and monoclinic Li₂MnO₃ at temperatures higher than 500 °C. The prepared samples were also characterized by FESEM and charge-discharge tests. The result showed that the specific capacity of 70.7 mAh/g was obtained within potential range of 4.2 to 2.5 V at constant current of 1.0 mA. The electrochemical performances of Li₄Mn₅O₁₂ material was further discussed in this paper.