Stabilizing Ni‐Rich LiNi_0.92Co_0.06Al_0.02O₂ Cathodes by Boracic Polyanion and Tungsten Cation Co‐Doping for High‐Energy Lithium‐Ion Batteries

Abstract

Layered nickel-rich transition metal oxide has been receiving much attention as high-energy-density cathode materials for rechargeable lithium-ion batteries. However, the severe capacity fading caused by bulk structural degradation of Ni-rich cathodes during lithiation/delithiation obstructs their commercialization. Herein, we modify the LiNi 0.92 Co 0.06 Al 0.02 O 2 (NCA92) cathode materials by W 6 + cation and BO 3 3À polyanion codoping to improve the structural stability and upgrade the electrochemical reversibility. The co-doped NCA92 materials show remarkably improved cycling stability at 1 C with a capacity retention of 93.4 % after 100 cycles, whereas the pristine cathodes exhibit poor capacity retention of 53.0 % and suffer severe structural deterioration. Further studies reveal that the particle fragmentation resulted from the inherent internal strain and the structural degradation upon cycling can be effectively mitigated by W 6 + cation and BO 3 3À polyanion codoping. Besides, W 6 + and BO 3 3À co-doping could enlarge the interlayer spacing of NCA92, thus increasing lithium-ion diffusion coefficient, which is conducive to enhancing the rate capability. The present work demonstrates that cationic-anionic co-doping is an effective strategy to maintain the structural stability of Ni-rich cathode materials, and it promotes the development of stable cathode materials for high energy density lithium-ion batteries.

Enhancing the Electrochemical Performance of Ni-Rich LiNi0.88Co0.09Al0.03O2 Cathodes through Tungsten-Doping for Lithium-Ion Batteries

“…What is more, Figure 4b shows the original peak of W 4f and its fitting peak. It can be seen that the binding energy of W 4f7/2 and W 4f5/2 are respectively located at 35.1 and 37.2 eV, which confirms the existence of W 6+ [15]. XPS measurements were performed to study the valence states of main elements, and all spectra were standardized with the C1s peak at 284.8 eV.…”

“…Among the commonly available LIB cathode materials, Ni-rich layered cathode materials, particularly LiNi x Co y TM 1−x−y O 2 , are believed to be the best choice of power sources for the current electric vehicles [6][7][8][9][10][11][12][13]. The LiNi 0.8 Co 0.15 Al 0.05 O 2 cathodes, for example, have been successfully applied to LIB to store electricity for Tesla electric vehicles, but it still has a cruising distance problem and insufficient cycle life [5,14,15]. It should be emphasized that the current strategy of achieving high energy densities in Ni-rich layered cathodes was to increase the nickel content, resulting in the development of LiNi 0.81 Co 0.15 Al 0.04 O 2 , LiNi 0.87 Co 0.1 Al 0.03 O 2 , and LiNi 0.88 Co 0.09 Al 0.03 O 2 [16][17][18][19].…”

“…In addition, the practical capacity of those commercial layered cathode materials with their nickel content near 80% has been limited to around 180–200 mAh g −1 to enhance cycle stability. And the comparatively high cobalt percentage is becoming increasingly problematic due to the soaring price of cobalt [ 3 , 15 , 27 , 28 , 29 ]. Therefore, it is a challenging task to develop Ni-rich cathodes with acceptable cycle stability.…”

Progress and Perspective: MXene and MXene‐Based Nanomaterials for High‐Performance Energy Storage Devices

“…[ 117,118 ] Nevertheless, research and development of novel electrode materials are still essential for the construction of high‐performance LIBs. [ 119–123 ] MXene is regarded as an ideal candidate for LIBs electrode materials due to the unique layered structure, excellent mechanical properties, electronic properties, and stability. [ 27,124–126 ] Thanks to the extraordinary characteristics, MXene and MXene‐based nanomaterials have been proved to be competitive electrode materials for high‐performance LIBs.…”

Dealloying-Derived Nanoporous Cu6Sn5 Alloy as Stable Anode Materials for Lithium-Ion Batteries

“…The development of portable electronic devices urgently requires lithium-ion batteries (LIBs) with a high capacity and long lifespan [ 1 , 2 , 3 ]. Currently, extensive efforts have been devoted to developing alternative anode materials, e.g., metal oxide, alloys and group IVA elements, to boost the capacity of LIBs [ 1 , 4 , 5 ].…”