Effects of Various Elements Doping on LiNi_0.6Co_0.2Mn_0.2O₂ Layered Materials for Lithium‐Ion Batteries

Abstract

As lithium-ion batteries (LIBs) have dominated the markets of communication and small devices, and marched into emerging fields such as electric vehicle, urgent requirements in the energy density have promoted ongoing search for cathode materials with high cycle and capability constancy. [1][2][3] Layered oxides LiNi x Co y Mn 1-x-y O 2 (NCM; 0 ≤ x, y, x þ y ≤ 1) of transition metals (TMs) with dense lattice overall possess high specific capacity per unit volume storage, especially for high nickel oxides (with 0.6 ≤ x þ y ≤ 1) that can deliver capacity up to 200 mAh g À1 . [4][5][6] However, these cathode materials still suffer from some drawbacks that limit the energy content of LIBs. For example, the increase in nickel content deteriorates the cycle stability despite improvement in the reversible specific capacity of the materials. [7][8][9] Such limiting factor induces the phase transitions and unavoidable Li þ /Ni 2þ mixing, leading to structural deformation and increased activation disorders. These features would seriously compromise the electrochemical properties of the materials. [10][11][12][13] The improvement of electrochemical properties of LiNi x Co y Mn 1-x-y O 2 materials by doping foreign elements has intensively adopted. For instance, Minsang et al. incorporated Cu into LiNi 1/3 Co 1/3 Mn 1/3 O 2 and found that the presence of Cu may reduce the mixing degree of Li þ /Ni 2þ , suppress the structural transformation, and improve the diffusion rate of Li þ . This, in turn, led to enhanced cycle performance and rate performance. [14] Other studies showed that Ti-doped Li(Ni x Mn x Co 1-2x-y Ti y )O 2 not only increased the energy density but also enhanced the structural stability upon cycling because of the elevated Ti-O bond energy. [15] Chen et al. reported that when F À occupied the O sites in Li-rich layered oxides, cycling stability was enhanced by 94.8% in 50 cycles between 2.0 and 4.8 V. [16] Small amounts of Fe-doped LiNi 1/3 Co 1/3 Mn 1/3 O 2 prepared by simple sol-gel method also displayed slight volume change in the material during Li þ diffusion, resulting in excellent structural stability. [17] In addition, other elements such as Al, [18,19] Cr, [20] Zr, [21,22] and Zn [23,24] have been also explored. Although extrinsic ions introduction can influence the performance of the LiNi x Co y Mn 1-x-y O 2 , it is difficult to evaluate and compare their contribution due to the test standard or preparation strategy, which is different from literature to literature. On the contrary, traditional preparation approaches such as solid-state method may induce uneven doping on host materials due to the loose adhesion and uneven distribution of the dopants. [22,[25][26][27] Motivated by the aforementioned research, herein, a series of metal-doped LiNi 0.6-x Co 0.2 Mn 0.2 M x (M ¼ Cr, Cu, Fe, Sn, and Zn) is synthesized and investigated. Their properties are measured and evaluated under the same condition to better understand their doping effects. In addition, in situ coprecipitation is used in this work to ...

A review on nickel-rich nickel–cobalt–manganese ternary cathode materials LiNi0.6Co0.2Mn0.2O2 for lithium-ion batteries: performance enhancement by modification

“…On the one hand, doping with electrochemically active elements, such as chromium (Cr), may limit the electrochemical performance to some extent. This was confirmed in the work published by Lu et al 57 in 2021, where the doping of Cr increased the charge transfer impedance and greatly reduced the cycling stability compared to Cu, Sn, and Zn doping; then, a comparison of the electrochemical properties is shown in Fig. 8b-d.…”

“…This was confirmed in the work published by Lu et al . 57 in 2021, where the doping of Cr increased the charge transfer impedance and greatly reduced the cycling stability compared to Cu, Sn, and Zn doping; then, a comparison of the electrochemical properties is shown in Fig. 8b–d.…”

High Value-Added Utilization of Waste Hydrodesulfurization Catalysts: Low-Cost Synthesis of Cathode Materials for Lithium-Ion Batteries

“…The results show that C-NCM material not only makes a show of not less than the S-NCM cycle performance, but it also shows excellent electrochemical performance under the condition of the same charge and discharge. This can be attributed to the introduction of trace impurity elements in the synthesis of C-NCM material, which is equivalent to the S-NCM material modified by multi-element doping [53][54][55][56][57][58][59]. Thus, the electrochemical properties and structural stabilities of materials are enhanced.…”

SiO2–GeO2 Glass–Ceramic Flakes as an Anode Material for High‐Performance Lithium‐Ion Batteries

“…Therefore, it is important to design and develop new anode materials and processing techniques to improve these drawbacks. Most published research on novel anode materials for LIBs has been concentrated on crystalline materials, such as carbon-based materials, [2,3] siliconbased materials [2,4,5] or transition metal oxides, [6,7] as they offer high specific capacities and densities. However, it is also known that crystalline anode materials undergo drastic microstructural changes during Li-ion insertion and extraction, which typically result in a massive volume expansion and shrinkage accompanied by detrimental mechanical stresses.…”

“…However, it is also known that crystalline anode materials undergo drastic microstructural changes during Li-ion insertion and extraction, which typically result in a massive volume expansion and shrinkage accompanied by detrimental mechanical stresses. [2,[4][5][6][7][8] These microstructural changes often result in mechanical breakage of the particle, which can be described as an "electrochemical milling," followed by further structural deterioration of the anode material. [9] Glass anode materials are known to be less sensitive to the swelling as they show a different behavior during Li-ion insertion: The detrimental swelling upon Li insertion is compensated by the free molar volume in the structure: Glasses exhibit a unique open network structural arrangement with no long-range order.…”