In this study, we investigate the two-dimensional copper boride, Cu8B14, as a possible anode material for lithium-ion batteries using first-principles calculations. We found that the structural integrity of the monolayer was preserved even at elevated temperatures, while electronic calculations confirm the metallic character of the pristine and Li-loaded systems. On systematic lithiation on Cu8
Nearby in the stack
B
14
a specific capacity of 430mAhg
−1
was obtained. A Li diffusion barrier of 0.32eV for the most favourable path, along with a diffusivity of approximately
2.26×10−5
cm
2
s
−1
was obtained. The open-circuit voltage of 0.53 V falls within the optimal anode range of 0.1--1.0 V. These combined characteristics point to Cu
8
B
14
as a compelling candidate for advanced battery anodes. Furthermore, to understand the defect and its effect on different parameters, we investigated an experimentally identified line-defect configuration of copper boride. The line defect monolayer retains a theoretical capacity of about 385mAhg
−1
, while the introduced line defect further reduces the Li migration barrier to 0.21eV, yielding an enhanced macroscopic diffusivity of
∼
5.6
×
10
−4
cm
2
s
−1
and confirming that structural defects accelerate Li-ion transport kinetics in this material.