Tellurium Surface Doping to Enhance the Structural Stability and Electrochemical Performance of Layered Ni-Rich Cathodes

Abstract

The Ni-rich layered oxides are considered as a candidate of next-generation cathode materials for high energy density lithium-ion batteries; however, the finite cyclic life and poor thermostability impede their practical applications. There is often a tradeoff between structure stability and high capacity because the intrinsical instability of oxygen framework will lead to the structural transformation of Ni-rich materials. Because of the strong binding energy between the Te atom and O atom, herein a new technology of surface tellurium (Te) doping in the Ni-rich layered oxide (LiNi0.88Co0.09Al0.03O2) is proposed to settle the above predicament. Based on density function theory calculations and experiment analysis, it has been confirmed that the doped Te6+ ions are positioned in the TM layer near the oxide surface, which can constrain the TM–O slabs by strong Te–O bonds and prevent oxygen release from the surface, thus enhancing the stability of the lattice framework in deep delithium (>4.3 V). Especially, 1 wt % Te doping (Te 1%-NCA) shows the superiority in performance improvement. Furthermore, the reversibility of H2–H3 phase transition is also improved to relieve effectively the capacity decline and the structural transformations at extended cycling, which can facilitate the fast Li+ diffusion kinetic. Consequently, Te 1%-NCA cathode exhibits the improved cycling stability even at high voltages (4.5 and 4.7 V), good rate capability (159.2 mA h g–1 at 10 C), and high thermal stability (the peak temperature of 258 °C). Therefore, the appropriate Te surface doping provides a significant exploration for industrial development of the high-performance Ni-rich cathode materials with high capacity and structural stability.

A Three in One Strategy to Achieve Zirconium Doping, Boron Doping, and Interfacial Coating for Stable LiNi0.8Co0.1Mn0.1O2 Cathode

“…For example, element doping has been proved to be one of the most effective strategies for mitigating the problems associated with irreversible transition. [10] Doping elements such as Al, Zr, Ti, Nd, Mo, B, and Mg have been reported. [11] Liu et al [12] confirmed that the lattice expansion can be suppressed when substituting the TMs with Ti.…”

Feasible synthesis of NCM811 cathodes with controllable Li/Ni cationic mixing for enhanced electrochemical performance via a nano grinding assisted solid‐state approach

“…[1][2][3] Lithium-ion batteries, with the advantages of cost, high operating voltage, and high discharge capacity, have been paid great attention. [4][5][6] As an indispensable and important part of lithium-ion batteries, cathode materials are also closely concerned by many researchers, hoping to provide cathode materials with excellent performance to meet the requirement from the customers. [7][8][9][10] At present, the cathode materials that have been commercialized in the market mainly include LiFePO 4 , [11][12][13] LiCoO 2 , [14][15][16] LiMn 2 O 4 , 17,18 and nickel-rich materials.…”

Metal‐Tellurium Batteries: A Rising Energy Storage System

“…[27] Wang and co-workers successfully integrated Te on the surface of nickel-rich layered oxide to significantly improve the structural stability and electrochemical performance of electrode for LIBs. [101] Currently, there are few reports on Te doping, and the related works are worthy of more exploration. In addition, the current Te doping technologies are mostly based on the ball milling of Te with active materials, which results in the relatively large size of the doped Te in system, so the feature of Te with high conductivity cannot be fully exhibited.…”