二维V_(3)CN对Na存储性能的理论研究

Theoretical study on the Na storage properties of two-dimensional V_(3)CN

过渡金属碳氮化物MXenes具有优异的储能和导电性能,被认为是发展前景广阔的金属离子电极材料。采用密度泛函理论计算方法,对钒三碳氮(V_(3)CN)材料对钠离子的存储行为进行了理论研究,并研究了V_(3)CN作为钠离子电池负极材料的可行性。计算结果表明,V_(3)CN具有稳定的结构,良好的电子导电性。V_(3)CN吸附单层钠离子时,平均吸附能为-0.682eV,负吸附能表明单层钠离子可以吸附在V_(3)CN基底上;V_(3)CN吸附双层钠离子时,平均吸附能为-0.03eV,吸附能仍为负值,并且单层、双层钠离子吸附在V_(3)CN基底后体系仍具有导电性能。V_(3)CN作为钠离子电池负极材料最大容量为599.57mAh/g。

Transition metal carbides and nitrides MXenes are considered to be promising metal ion electrode materials due to their excellent energy storage and electrical conductivity.In this paper,density functional theory calculation method was used to study the storage behavior of V_(3)CN materials for Na ions,and the feasibility of V_(3)CN as anode material for sodium ion batteries was studied.The calculation results showed that V_(3)CN had a stable structure and good electronic conductivity.When V_(3)CN adsorbed single layer Na ions,the average adsorption energy was-0.682eV,and the negative adsorption energy indicated that single layer Na ions could be adsorbed on the V_(3)CN substrate.When V_(3)CN adsorbed double layer Na ions,the average adsorption energy was-0.03eV,which was still negative.Moreover,the system still had electrical conductivity after single layer and double layer Na adsorbed on the V_(3)CN substrate.The maximum capacity of V_(3)CN as anode material for sodium ion batteries was 599.57mAh/g.