Aluminum doping and lithium tungstate surface coating double effect to improve the cycle stability of lithium-rich manganese-based cathode materials

Abstract

Al doped lithium-rich manganese-based Li1.2Mn0.54−xAlxNi0.13Co0.13O2 (x = 0, 0.03) cathode materials for lithium-ion batteries were synthesized with sol-gel method, and then Li2WO4 coating was prepared by one-step liquid phase method. The effects of Al doping and Li2WO4 coating on the electrochemical properties of lithium-rich manganese-based cathode materials were systematically studied. The results show that Al doping significantly improves the cycle stability of lithium-rich manganese-based cathode material, and the coating Li2WO4 significantly improves its magnification performance and the voltage attenuation of discharge plateau. The coating amount of Li2WO4 is 5%, and the specific capacity of Li1.2Mn0.51Al0.03Ni0.13Co0.13O2 cathode material is still up to about 110 mAh·g−1 in the charge and discharge voltage range of 2.0-4.8 V and the current density of 1,000 mA·g−1. At the same time, the capacity retention rate of 300 cycles at the current density of 100 mA·g−1 is 78%, and the voltage attenuation of the discharge plateau during the cycle is also significantly reduced. This work provides a new idea for solving the cycle stability and platform voltage attenuation of lithium-ion battery lithium-rich manganese-based cathode materials.

Opportunities and Challenges of Layered Lithium-Rich Manganese-Based Cathode Materials for High Energy Density Lithium-Ion Batteries

“…This also greatly limits its rate capability. Since the conductivity of ions and electrons is the main factor for the rate performance, many modification methods focus on the improvement of their rate performance, such as by doping, − surface coating, − construction of three-dimensional layered spinel heterostructures, and so on. However, the transmission path and particle size affect the electronic and ionic conductivity.…”

Effects of Fe and Li2MnO3‐like domains on structural stability in Co‐free Li‐rich layered oxide cathodes

“…However, some problems such as low initial coulombic efficiency (ICE), severe capacity/voltage fading during cycling and poor rate performance derived from the excessive oxidation of lattice oxygen seriously hinder LLOs' commercial applications [9,[15][16][17][18]. Many methods, such as bulk doping [19][20][21] and surface modification [22][23][24] have been carried out to restrain these drawbacks.…”