Preparation,characterization, and evaluation of LiNi0.4Co0.6O2 nanofibers for supercapacitor applications

We prepared LiNi_0.4Co_0.6O₂ nanofibers by electrospinning at the calcination temperature of 450 °C for 6 h. The prepared LiNi_0.4Co_0.6O₂ nanofibers was characterized by thermal, X-ray diffraction, and Fourier transform infrared (FTIR) studies. The morphology of LiNi_0.4Co_0.6O₂ nanofibers was characterized by scanning electron microscopy studies. The asymmetric supercapacitor was fabricated using LiNi_0.4Co_0.6O₂ nanofibers as positive electrode and activated carbon (AC) as negative electrode and a porous polypropylene separator in 1 M LiPF₆–ethylene carbonate/dimethyl carbonate (LiPF₆–EC:DMC) (1:1?v/v) as electrolyte. Cyclic voltammetry studies were then carried out in the potential range of 0 to 3.0 V at different scan rates which exhibited the highest specific capacitance of 72.9 F g^?1. The electrochemical impedance measurements were carried out to find the charge transfer resistance and specific capacitance of the cell, and they were found to be 5.05 Ω and 67.4 F g^?1, respectively. Finally, the charge–discharge studies were carried out at a current density of 1 mA cm^?2 to find out the discharge-specific capacitance, energy density, and power density of the capacitor cell, and they were found to be 70.9 F g^?1, 180.2 Wh kg^?1, and 248.0 W kg^?1, respectively.     

Synthesis and characterization of LiNi1/3Co1/3Mn1/3O2 cathode material for rechargeable lithium batteries by polyacrylic acid-assisted sol–gel method

Nanocrystalline LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials are synthesized by sol–gel method using polyacrylic acid as a chelating agent. The effects of the calcination temperature and calcination time on the structure, morphology, and electrochemical performances of the LiNi_1/3Co_1/3Mn_1/3O₂ electrode materials are investigated by X-ray diffraction, scanning electron microscopy and charge–discharge cycling test, respectively. All experiments show that the microscopic structural features and the morphology properties are deeply related with the electrochemical performance. The results show that the nanocrystalline LiNi_1/3Co_1/3Mn_1/3O₂ with a particle size of 80 nm sintered at 700 °C for 2 h presents good α-NaFeO₂ layer structure and the best electrochemical performance. When it is discharged between 4.4 and 2.8 V at 20 mAg^?1, the initial specific capacity of the LiNi_1/3Co_1/3Mn_1/3O₂ obtained at 700 °C for 2 h is 169.2 mAhg^?1. The investigated electrode materials retain 151 mAhg^?1 after 30 cycles when cycled at 20 mAg^?1.     

Effects of acid treatment on electrochemical properties of Li<Subscript>2</Subscript>MnO<Subscript>3</Subscript>·LiNi<Subscript>0.5</Subscript>Co<Subscript>0.45</Subscript>Fe<Subscript>0.05</Subscript>O<Subscript>2</Subscript> cathode materials

A new composite, Li₂MnO₃·LiNi_0.5Co_0.45Fe_0.05O₂, can be synthesized by a solid-state method and preconditioned with 5 wt% HCl, H₂SO₄, or H₃PO₄ solution to achieve H⁺/Li⁺ exchange. The effects of acid treatment on the structure, morphology, and electrochemical properties of Li₂MnO₃·LiNi_0.5Co_0.45Fe_0.05O₂ cathode materials are analyzed. The X-ray powder diffraction patterns imply that the hexagonal α-NaFeO₂ structure (space group R\(\bar{3}\)m) of the materials is not changed by the acid treatment. The scanning electron microscope images show that particles become spherical with smooth surfaces after acid treatment, and the Brunauer–Emmett–Teller analysis reveals that the specific surface area increases. The charge–discharge test demonstrates that acid-treated Li₂MnO₃·LiNi_0.5Co_0.45Fe_0.05O₂ cathode materials deliver higher initial coulombic efficiencies than untreated material, owing to the improvement of the catalytic reduction activity of oxygen released during the initial charge process. Furthermore, Li₂MnO₃·LiNi_0.5Co_0.45Fe_0.05O₂ treated with HCl displays the best electrochemical performance, with the acid treatment improving the initial coulombic efficiency from 66.0 to 82.2%. Thus, acid treatment can effectively improve the electrochemical performance of electrode materials in Li-ion batteries.     

Effect of LiPF<Subscript>6</Subscript> on the thermal behaviors of four organic solvents for lithium ion batteries

The thermal behaviors of four organic solvents with/without LiPF₆ were measured by C80 microcalorimeter at a 0.2°C min⁻¹ heating rate. With the addition of 1 M LiPF₆, the ethylene carbonate (EC) and propylene carbonate (PC) show the exothermic peaks at elevated temperature, which lessen their stabilities. The exothermic peak temperatures of EC and PC based LiPF₆ solutions are at 212 and 223°C, respectively, in argon filled vessel. However, two endothermic peak temperatures were detected in diethyl carbonate (DEC) based LiPF₆ solution at 182 and 252.5°C, respectively, in argon filled vessel. Dimethyl carbonate (DMC) based LiPF₆ solution shows two endothermic peak temperatures at 68.5 and 187°C in argon filled vessel at elevated temperature. Consequently, it is concluded that LiPF₆ play a key role in the thermal behavior of its organic solution.     

Vinyl-functionalized imidazolium ionic liquids as new electrolyte additives for high-voltage Li-ion batteries

Four functionalized ionic liquids based on imidazolium cations with vinyl or alllyl group and TFSI^? anion were synthesized as electrolyte additives for high-voltage Li-ion battery to stabilize carbonate-based electrolytes on the surface of 5 V class cathode materials. The electrochemical behaviors and surface morphology of LiNi_0.5Mn_1.5O₄ cathode had been investigated by cyclic voltammetry, charge–discharge test, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), respectively. Cycle life and rate performance of the Li/LiNi_0.5Mn_1.5O₄ cells containing 1.2 M LiPF₆ in ethylene carbonate/ethyl methyl carbonate can be improved by adding 1-allyl-3-vinyl imidazolium bis(trifluoromethanesulphonyl)imide ([AVIm][TFSI]). The addition of 3 wt.% [AVIm][TFSI] results in high discharge capacity of above 130 mAh g^?1. Surface analysis of the cathode material (XPS and SEM) suggested that a stable and compact polymer film was formed on the LiNi_0.5Mn_1.5O₄ cathode by electroinitiated polymerization of imidazolium cation with vinyl and allyl group.     

Effect of Li2O-doping on the thermal stability of cobaltic oxide

The influence of lithium oxide-doping on the thermal stability of Co₃O₄ was studied using DTA, TG, DTG and X-ray diffraction techniques. Pure and doped cobaltic oxide specimens were prepared by thermal decomposition of pure basic cobalt carbonate and the basic carbonate mixed with different proportions of LiOH, in air, at different temperatures between 500 and 1100°C.Pure Co₃O₄ was found to start partial decomposition when heated in air at 830°C yielding the CoO phase. The complete decomposition was effected by heating at 1000°C.Doping of Co₃O₄ with different proportions of Li₂O was found to much increase its thermal stability. The temperatures at which the doped oxide samples started to undergo decomposition were increased to 865, 910 and 1050°C for 0.375, 0.75 and 3% Li₂O-doped solids, respectively. The DTA revealed that the 1.5% Li₂O-doped cobaltic oxide did not undergo any thermal decomposition till 1080°C. The X-ray investigation showed that the prolonged heating of 1.5 and 3% Li₂O-doped solids at 1100°C for 36 h effected only a partial decomposition of Co₃O₄ into CoO. Heating of these solids at temperatures varying between 900 and 1100°C led also to the formation of a new lithium oxide cobaltic oxide phase, the composition of which has not yet been identified.The role of Li₂O in increasing the thermal stability of Co₃O₄ was attributed to the substitution of some of its cobalt ions by Li⁺ ions, according to Verwey and De Boer's mechanism, leading to the transformation of some of the Co²⁺ into Co³⁺ ions thus increasing the oxidation state of the cobaltic oxide lattice.     

Thermal instabilities of organic carbonates with discharged cathode materials in lithium-ion batteries

Thermal instability of lithiated cathode materials with organic carbonate were investigated using DSC. Lithium transition metal oxides of LiFePO₄, LiMn₂O₄, and LiCoO₂ were mixed with diethyl carbonate, dimethyl carbonate, ethylene carbonate, ethyl methyl carbonate, and propylene carbonate then dynamically screened to about 500 °C. Curves were acquired and analyzed to determine exothermic onset temperatures and reaction enthalpies. These data for assessing the thermal hazards of lithium-ion batteries under discharged conditions were compared to those data published in the literature.     

Improved electrochemical performance of LiNi0.5Mn1.5O4 as cathode of lithium ion battery by Co and Cr co-doping

Three samples, LiNi_0.5Mn_1.5O₄, LiNi_0.4Mn_1.4Co_0.2O₄, and LiNi_0.4Mn_1.4Cr_0.15Co_0.05O₄, were prepared by sol–gel method and characterized by powder X-ray diffraction, Fourier transformed infrared spectroscope, scanning electron microscopy, Brunauer–Emmett–Teller surface area, four-probe resistance, cyclic voltammetry, electrochemical impedance spectroscopy, and charge–discharge test. It is found that the co-doped sample LiNi_0.4Mn_1.4Cr_0.15Co_0.05O₄ exhibits an improved performance compared with the Co-doped sample LiNi_0.4Mn_1.4Co_0.2O₄ and the undoped sample LiNi_0.5Mn_1.5O₄, especially at elevated temperature. At 25 °C, the discharge capacity of LiNi_0.4Mn_1.4Cr_0.15Co_0.05O₄ is 130 mAh g^?1 at 0.1 C and 103 mAh g^?1 at 10 C. At an elevated temperature (55 °C), its 1 C discharge capacity is 136 mAh g^?1 and maintains 95.6 % of its initial capacity after 100 cycles. Compared with the reported results of LiNi_0.4Mn_1.4Co_0.2O₄ and LiNi_0.475Mn_1.475Co_0.05O₄, the co-doped sample LiNi_0.4Mn_1.4Cr_0.15Co_0.05O₄, with least content of Co, 0.05, possesses not only the high C-rate capacity but also the structural stability. The mechanism on the electrochemical performance improvement of LiNi_0.5Mn_1.5O₄ by the co-doping was discussed.     

Towards high-performance cathode materials for lithium-ion batteries: Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-coated LiNi<Subscript>0.8</Subscript>Co<Subscript>0.15</Subscript>Zn<Subscript>0.05</Subscript>O<Subscript>2</Subscript>

Zn-doped LiNi_0.8Co_0.2O₂ exhibits impressive electrochemical performance but suffers limited cycling stability due to the relative large size of irregular and bare particle which is prepared by conventional solid-state method usually requiring high calcination temperature and prolonged calcination time. Here, submicron LiNi_0.8Co_0.15Zn_0.05O₂ as cathode material for lithium-ion batteries is synthesized by a facile sol-gel method, which followed by coating Al₂O₃ layer of about 15 nm to enhance its electrochemistry performance. The as-prepared Al₂O₃-coated LiNi_0.8Co_0.15Zn_0.05O₂ cathode delivers a highly reversible capacity of 182 mA h g^?1 and 94% capacity retention after 100 cycles at a current rate of 0.5 C, which is much superior to that of bare LiNi_0.8Co_0.15Zn_0.05O₂ cathode. The enhanced electrochemistry performance can be attributed to the Al₂O₃-coated protective layer, which prevents the direct contact between the LiNi_0.8Co_0.15Zn_0.05O₂ and electrolyte. The escalating trend of Li-ion diffusion coefficient estimated form electrochemical impedance spectroscopic (EIS) also indicate the enhanced structural stability of Al₂O₃-coated LiNi_0.8Co_0.15Zn_0.05O₂, which rationally illuminates the protection mechanism of the Al₂O₃-coated layer.     

Low temperature synthesis of Li5La3Nb2O12 with cubic garnet-type structure by sol–gel process

A cubic Li₅La₃Nb₂O₁₂ phase with a garnet framework was synthesized by the sol–gel process, in which lithium hydroxide, niobium oxide and acetic lanthanum were used as starting materials, while water was used as solvent. Pure garnet-like Li₅La₃Nb₂O₁₂ powders were obtained after heating the gel precursor at 700 °C for 6 h with 10 % excess lithium salt. The calcination temperature is nearly 250 °C lower than that by the solid state reaction. The phase transforms from cubic to tetragonal symmetry with loss of lithium at 717 °C, but the garnet framework remains stable to above 900 °C. A pellet annealed at 900 °C for 6 h had a room-temperature Li⁺-ion conductivity σ_Li (22 °C) = 1.0 × 10^?5 S cm^?1, a little higher than that attained by solid-state synthesis. The Li₅La₃Nb₂O₁₂ compound was chemically stable against two commonly used cathode materials, LiMn₂O₄ and LiCoO₂, up to 900 °C and against metallic lithium.     

Investigation of the gas evolution in lithium ion batteries: effect of free lithium compounds in cathode materials

The evolution of gas in lithium ion batteries (LIBs) was investigated. The large amount of gas emission related to a charged cathode has been a critical issue because it causes deformation and performance degradation of LIBs. This study examined the effect of free lithium compounds such as Li₂CO₃ or LiOH on gas generation, which revealed several different features comparing with gas generation related to the cathode active materials themselves: CO₂ was the main gas generated, chain-structured carbonate solvents such as dimethyl carbonate or ethyl methyl carbonate generated more gas than cyclic-structured ethylene carbonate, and the gas generation did not occur without LiPF₆ in the electrolyte solution. These were found to be the main reason for the different gas-generating behaviors between LiCoO₂ (LCO) and LiNi_0.85Co_0.12Al_0.03O₂ (NCA) cathodes. For LCO, which has a very small amount of free lithium compounds on the surface, the gas was generated mainly by a reaction between delithiated LCO itself and the electrolyte solution, whereas a considerable amount of gas was generated by surface free lithium for NCA. Therefore, the removal of free lithium compounds is essential, particularly for NCA, to prevent the swelling of LIBs.     

Improved molten salt synthesis and structure evolution upon cycling of 0.5Li2MnO3·0.5LiCoO2 in lithium-ion batteries

The Li-rich cathode material Li_1.2Co_0.4Mn_0.4O₂(=0.5Li₂MnO₃·0.5LiCoO₂) was prepared by an improved molten salt method. The effects of sintering temperature and time on the physical and electrochemical properties of Li_1.2Co_0.4Mn_0.4O₂ were investigated. With increasing sintering temperature, excellent crystallinity and a stable structure are obtained, which lead to excellent electrochemical properties. However, the sample sintered at 900 °C has poor performance because its large powder diameter prolongs the transportation length of Li⁺ ions. Higher specific surface areas are obtained when samples are sintered at 850 °C for a shorter time, which leads to more activity and excellent charge/discharge capacity. The evolution of a derivative peak at about 3.0 V in the differential capacity (dQ/dV) curves is observed along with the formation of a spinel-like phase, which is verified by analysis using a high-resolution transmission electron microscope. Therefore, it is a simple and quick method to characterize the structure evolution upon cycling of Li-rich cathode materials by means of analysis of the derivative peak.     

Synergistic Dual‐Additive Electrolyte Enables Practical Lithium‐Metal Batteries

A rechargeable Li metal anode coupled with a high‐voltage cathode is a promising approach to high‐energy‐density batteries exceeding 300 Wh kg^?1. Reported here is an advanced dual‐additive electrolyte containing a unique solvation structure and it comprises a tris(pentafluorophenyl)borane additive and LiNO₃ in a carbonate‐based electrolyte. This system generates a robust outer Li₂O solid electrolyte interface and F‐ and B‐containing conformal cathode electrolyte interphase. The resulting stable ion transport kinetics enables excellent cycling of Li/LiNi_0.8Mn_0.1Co_0.1O₂ for 140 cycles with 80 % capacity retention under highly challenging conditions (≈295.1 Wh kg^?1 at cell‐level). The electrolyte also exhibits high cycling stability for a 4.6 V LiCoO₂ (160 cycles with 89.8 % capacity retention) cathode and 4.95 V LiNi_0.5Mn_1.5O₄ cathode.     

Comprehensive reinvestigation on the initial coulombic efficiency and capacity fading mechanism of LiNi0.5Mn1.5O4 at low rate and elevated temperature

The effect of different membranes and aluminum current collectors on the initial coulombic efficiency of LiNi_0.5Mn_1.5O₄/Li was investigated, and the cycling performance at different rates and temperatures and the storage performance at 60 °C for a week are discussed for LiNi_0.5Mn_1.5O₄/Li. The results show that the lower initial coulombic efficiency is associated with the lower decomposition voltage of the commercial membrane and electrolyte, and the instability of aluminum current collector under the higher voltage. In addition, both versions of LiNi_0.5Mn_1.5O₄ can deliver about 115 mA?h g^?1 of initial discharge capacity at 1 C at 25 °C and 60 °C; however, it retains only 61.57 % of its initial capacity after the 130th cycles at 60 °C, which is much lower than the 94.46 % rate observed for LiNi_0.5Mn_1.5O₄ at 25 °C, and the cycling performance of the material at 1 C is better than that at 0.5 C. Meanwhile, the initial discharge capacity at 0.1 C after storing at 60 °C is 119.3 mA?h g^?1, which is only a little lower than 121.5 mA?h g^?1 recorded before storing; moreover, the spinel structure and surface state of LiNi_0.5Mn_1.5O₄ after storing at 60 °C has not been changed basically. These results indicate that the electrochemical stability of electrolyte is also related to the temperature. The serious capacity fading of LiNi_0.5Mn_1.5O₄ at 60 °C is attributed to the severe oxidation decomposition and the thermal decomposition in the range of cut-off voltage of the materials, and then the decomposition products interact with active materials to form a solid interface phase, leading to the larger electrode polarization and irreversible capacity loss. Meanwhile, the worse cycling performance at 0.5 C than that at 1 C is attributed to the longer interaction time between the electrolyte and the active materials. However, the storage performance of LiNi_0.5Mn_1.5O₄ corresponds to the thermal stability of electrolyte to a certain extent.     

流变相法合成LiNi0.85Co0.15O2的结构与电化学性能

以一种新型的软化学方法——流变相法, 成功地合成了锂离子电池正极材料LiNi_0.85Co_0.15O₂. 将在600～850 ℃氧气氛下处理6 h后得到的LiNi_1－yCo_yO₂ (y＝0.10, 0.15, 0.20, 0.25), 进行X射线粉末衍射(XRD)与电化学测试. 测试结果表明, 流变相前体经过800 ℃烧结后合成的LiNi_0.85Co_0.15O₂晶胞参数a＝0.2866 nm, c＝1.4193 nm及晶胞体积V＝0.1010 nm³, 以0.1 C倍率在3.0～4.3 V (vs. Li^＋/Li)放电时, 首次放电容量可以达到198.2 mAh/g, 20次循环后, 其放电容量仍在174 mAh/g以上.     

LixNi0.5Co0.5O2的态密度计算及电化学性能研究

>为获得综合性能更好的锂离子二次电池正极材料, 分析了Co掺杂对Li_xNiO₂电化学性能的影响. 采用密度泛函DFT理论对Li_xNiO₂和Li_xNi_0.5Co_0.5O₂的平均放电电压和态密度进行了计算. 同时, 用共沉淀法制备了Li_xNiO₂和Li_xNi_0.5Co_0.5O₂锂离子二次电池正极材料, 并对其进行了XRD结构分析和恒流充放电测试. 实验和计算结果表明: 随锂离子嵌入正极(电池放电), 电池的电压逐渐降低, 材料的态密度峰向低能量方向移动; 与Li_xNiO₂相比, Li_xNi_0.5Co_0.5O₂的电压平台相对较高(当0.25≤x≤0.5), 而且在Li^＋嵌/脱时, Li_xNi_0.5Co_0.5O₂的结构变化相对较小; Co离子的掺入, 减小了NiO₆八面体的畸变度, 使材料的电化学稳定性得以提高. 在钴掺杂镍酸锂体系中, NiO₆和CoO₆具有相互的稳定作用.     

A facile synthesis of non-aqueous LiPO2F2 solution as the electrolyte additive for high performance lithium ion batteries

Constructing a reliable and favorable electrode-electrolyte interface is crucial to utilize the exceptional energy storage capability in commercial lithium-ion batteries. Here, we report a facile synthesis approach for the lithium difluorophosphate (LiPO₂F₂) solution as an effective film-forming additive via direct adding the Li₂CO₃ into LiPF₆ solution at 45 °C. Benefiting from the significantly reduced interface resistance (R_SEI) and charge transfer impedance (R_ct) of both the cathode and anode by adding the prepared LiPO₂F₂ solution into a baseline electrolyte, the cycling performance of the graphite||LiNi_0.5Mn_0.3Co_0.2O₂ pouch cell is remarkably improved under all-climate condition.     

Co-precipitation spray-drying synthesis and electrochemical performance of stabilized LiNi<Subscript>0.5</Subscript>Mn<Subscript>1.5</Subscript>O<Subscript>4</Subscript> cathode materials

In this paper, the LiNi_0.5Mn_1.5O₄ cathode materials of lithium-ion batteries are synthesized by a co-precipitation spray-drying and calcining process. The use of a spray-drying process to form particles, followed by a calcination treatment at the optimized temperature of 750 °C to produce spherical LiNi_0.5Mn_1.5O₄ particles with a cubic crystal structure, a specific surface area of 60.1 m² g^?1, a tap density of 1.15 g mL^?1, and a specific capacity of 132.9 mAh g^?1 at 0.1 C. The carbon nanofragment (CNF) additives, introduced into the spheres during the co-precipitation spray-drying period, greatly enhance the rate performance and cycling stability of LiNi_0.5Mn_1.5O₄. The sample with 1.0 wt.% CNF calcined at 750 °C exhibits a maximum capacity of 131.7 mAh g^?1 at 0.5 C and a capacity retention of 98.9% after 100 cycles. In addition, compared to the LiNi_0.5Mn_1.5O₄ material without CNF, the LiNi_0.5Mn_1.5O₄ with CNF demonstrates a high-rate capacity retention that increases from 69.1% to 95.2% after 100 cycles at 10 C, indicating an excellent rate capability. The usage of CNF and the synthetic method provide a promising choice for the synthesis of a stabilized LiNi_0.5Mn_1.5O₄ cathode material.

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Graphical Abstract Micro/nanostructured LiNi_0.5Mn_0.5O₄ cathode materials with enhanced electrochemical performances for high voltage lithium-ion batteries are synthesized by a co-precipitation spray-drying and calcining routine and using carbon nanofragments (CNFs) as additive.

     

A simple and effective strategy to synthesize Al2O3-coated LiNi0.8Co0.2O2 cathode materials for lithium ion battery

A facile method has been developed to synthesize Al₂O₃-coated LiNi_0.8Co_0.2O₂ cathode materials. The sample was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and energy dispersive analysis of X-rays (EDAX). Electrochemical tests show that the cycling stability of LiNi_0.8Co_0.2O₂ at room temperature is effectively improved by Al₂O₃ coating. The differential scanning calorimetry (DSC) and high temperature (60 °C) cycling tests indicate that Al₂O₃ coating can also improve the thermal stability of LiNi_0.8Co_0.2O₂, which is attributed to that the coating layer can protect the LiNi_0.8Co_0.2O₂ particles from reacting with the electrolyte.     

Sn-doped Li<Subscript>1.2</Subscript>Mn<Subscript>0.54</Subscript>Ni<Subscript>0.13</Subscript>Co<Subscript>0.13</Subscript>O<Subscript>2</Subscript> cathode materials for lithium-ion batteries with enhanced electrochemical performance

Sn-doped Li-rich layered oxides of Li_1.2Mn_0.54-x Ni_0.13Co_0.13Sn _x O₂ have been synthesized via a sol-gel method, and their microstructure and electrochemical performance have been studied. The addition of Sn⁴⁺ ions has no distinct influence on the crystal structure of the materials. After doped with an appropriate amount of Sn⁴⁺, the electrochemical performance of Li_1.2Mn_0.54-x Ni_0.13Co_0.13Sn _x O₂ cathode materials is significantly enhanced. The optimal electrochemical performance is obtained at x = 0.01. The Li_1.2Mn_0.53Ni_0.13Co_0.13Sn_0.01O₂ electrode delivers a high initial discharge capacity of 268.9 mAh g^?1 with an initial coulombic efficiency of 76.5% and a reversible capacity of 199.8 mAh g^?1 at 0.1 C with capacity retention of 75.2% after 100 cycles. In addition, the Li_1.2Mn_0.53Ni_0.13Co_0.13Sn_0.01O₂ electrode exhibits the superior rate capability with discharge capacities of 239.8, 198.6, 164.4, 133.4, and 88.8 mAh g^?1 at 0.2, 0.5, 1, 2, and 5 C, respectively, which are much higher than those of Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ (196.2, 153.5, 117.5, 92.7, and 43.8 mAh g^?1 at 0.2, 0.5, 1, 2, and 5 C, respectively). The substitution of Sn⁴⁺ for Mn⁴⁺ enlarges the Li⁺ diffusion channels due to its larger ionic radius compared to Mn⁴⁺ and enhances the structural stability of Li-rich oxides, leading to the improved electrochemical performance in the Sn-doped Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ cathode materials.