Enhanced structural and electrochemical stability of LiNi0.83Co0.11Mn0.06O2 cathodes by zirconium and aluminum co-doping for lithium-ion battery

Min

ACS Appl. Mater. Interfaces

2022

The synergistic effect of Na + /Al 3+ dual doping is investigated to improve the structural stability and electrochemical performance of LiNi 0.88 Co 0.08 Mn 0.04 O 2 cathodes for Li-ion batteries. Rietveld refinement and density functional theory calculations confirm that Na + /Al 3+ dual doping changes the lattice parameters of LiNi 0.88 Co 0.08 Mn 0.04 O 2 . The changes in the lattice parameters and degree of cation mixing can be alleviated by maintaining the thickness of the LiO 6 slab because the energy of Al−O bonds is higher than that of transition metal (TM)−O bonds. Moreover, Na is an abundant and inexpensive metal, and unlike Al 3+ , Na + can be doped into the Li slab. The ionic radius of Na + (1.02 Å) is larger than that of Li + (0.76 Å); therefore, when Na + is inserted into Li sites, the Li slab expands, indicating that Na + serves as a pillar ion for the Li diffusion pathway. Upon dual doping of the Li and TM sites of Ni-rich Ni 0.88 Co 0.08 Mn 0.04 O 2 (NCM) with Na + and Al 3+ , respectively, the lattice structure of the obtained NNCMA is more ideal than those of bare NCM and Li + -and Na + -doped NCM (NNCM and NCMA, respectively). This suggests that NNCMA with an ideal lattice structure presents several advantages, namely, excellent structural stability, a low degree of cation mixing, and favorable Li-ion diffusion. Consequently, the rate capability of NNCMA (83.67%, 3 C/0.2 C), which presents favorable Li-ion diffusion because of the expanded Li sites, is higher than those of bare NCM (78.68%), NNCM (81.15%), and NCMA (83.18%). The Rietveld refinement, differential capacity analysis, and galvanostatic intermittent titration technique results indicate that NNCMA exhibits low polarization, favorable Li-ion diffusion, and a low degree of cation mixing; moreover, its phase transition is hindered. Consequently, NNCMA demonstrates a higher capacity retention (84%) than bare NCM (79%), NNCM (82%), and NCMA (82%) after 50 cycles at 1 C. This study provides insight into the fabrication of Ni-rich NCMs with excellent electrochemical performance. KEYWORDS: cathode material, Li-ion battery, LiNi 0.88 Co 0.08 Mn 0.04 O 2 , Na doping, Al doping, dual doping

Section: ■ Results and Discussionmentioning

confidence: 86%

Section: ■ Results and Discussionmentioning

confidence: 86%

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Synergistic Effect of Na⁺ and Al³⁺ Dual Doping on Electrochemical Performance and Structural Stability of LiNi_0.88Co_0.08Mn_0.04O₂ Cathodes for Li-Ion Batteries

Min

ACS Appl. Mater. Interfaces

2022

“…A new concept of codoping of zirconium and aluminum in the cathode materials has become apparent to enhance the characteristics at the atomic scale. [ 69 ] Zr 4+ /Al 3+ codoped material in a nickel‐rich LiNi 0.83 Co 0.11 Mn 0.06 O 2 cathode induced a stable shell on the doped layer of the cathode composite. Effective stabilization of the internal morphology of the film with reduced interfacial parasitic reactions and phase transformation was achieved as a result of the codoping synergistic effect.…”

Section: Formation and Modification Of The Ceimentioning

confidence: 99%

Understanding the Cathode–Electrolyte Interphase in Lithium‐Ion Batteries

et al. 2022

The electrode–electrolyte interface is one of the major components enabling Li‐ion batteries (LIBs) to function reversibly. Often, the solid–electrolyte interphase (SEI) at the anode is regarded as the key interface that determines the cycle life, capacity fade, and overall safety of batteries. There are a plethora of SEI literatures that exist; however, the cathode–electrolyte interphase (CEI) remains relatively unexplored. Unlike in the case of SEI, a detailed understanding of CEI formation and its association with battery performance is not present. This review gives insight into the recent progress in understanding the CEI in LIBs. Though there is a relative dearth of literature, the CEI is generally considered as a heterogeneous multicomponent film formed due to the decomposition of electrolyte at the cathode surface. Besides understanding the thermodynamic properties and relevant kinetic reactions, one of the main challenges lies in developing and stabilizing the CEI layer due to its complex structural composition. Extensive research efforts to engineer a stable CEI are reviewed, including the use of electrolyte additives, artificial engineering, and heteroatom doping of cathode. Furthermore, promising characterization techniques and future outlook in forming a robust CEI for both existing LIB and post‐LIB systems are highlighted.

Grain Morphology and Microstructure Control in High‐Stable Ni‐Rich Layered Oxide Cathodes

Wang

Zhu

Xiao

et al. 2023

Adv Funct Materials

Ni-rich layered oxides are promising cathode material for high-energy-density lithium-ion batteries (LIBs). However, they suffer from poor capacity retention due to unstable structures. Herein, a strategy of high-valence W doping is put forward to tune the nanometer-sized crystal domains and reshape the primary particle textures, which can stabilize the structure against the formation of microcracks to improve the electrochemical performance. The Ni-rich layered oxide with 0.5 mol% doped W delivers a high-capacity retention of 91.6% up to 300 cycles under 1 C. Such an improved performance is ascribed to the pre-introduced nanometer-sized spinel and rock-salt crystal domains, which remarkably improve the structure stability, and the radially alignment of primary particles, and effectively reduce the anisotropic mechanical strain in deep charge states. This study sheds light on the design of high-performance Co-less Ni-rich cathode materials through the adjustment of microstructures via a small amount of suitable dopants.