高镍单晶层状三元正极材料的高熵策略掺杂改性研究OA

LiNixCoyMn1-x-yO2(NCM,x≥0.8),a promising cathode material for lithium-ion batteries,possesses high energy density and excellent discharge performance.However,it also appears drawbacks such as severe cation disorder,poor cycling performance and insecurity at high temperatures and high cut-off voltages.In this study,a high-entropy(HE)doping modification strategy was introduced into a high-nickel and low-cobalt LiNi0.86Co0.04Mn0.1O2 cathode material,and a high-nickel single-crystal layered ternary cathode material was synthesized by a high-temperature solid-state reaction method.The results show that at 0.1C(1C=180 mA·g-1)and 25℃,the battery equipped with modified material has a reversible discharge capacity of 197 mAh·g-1 and exhibits excellent discharge performance at high temperatures and high cut-off voltages.At 0.5C,55℃and 4.3 V,the discharge capacity reaches 281 mAh·g-1,while at 0.5C,25℃and 4.5 V,the discharge capacity is as high as 194 mAh·g-1.This material has a good layered structure with a uniform arrangement of nanoscale primary particles at microscale and a smaller total impedance.This work significantly improves cycling performance and safety of high-nickel ternary cathode materials at high temperatures and high cut-off voltages,providing a good modification method for the cobalt-free,high-nickel and practical application of ternary materials.