**Conflict of interest**

*Nanorods and Nanocomposites*

adsorption of Li.

*aligned CNT [51].*

**Figure 17.**

**3. Conclusion**

materials.

**Acknowledgements**

research support.

along with the capacity of lithium [52].

onto the vertically aligned CNT decreases the path for diffusion of Li and aids the

*Li adsorption on (a) CNT, (b) vanadium oxide, (c) and (d) composite of vanadium oxide on vertically* 

Cui et al. presented the composite of orthorhombic MoO3 and graphene as a cathode in LIBs with higher conductivity and adsorption of lithium. They studied the structure in bulk form as well as the monolayer structure. They have established that the Li charge and discharge rate have increased in the composite structure

In conclusion, we can say that the carbon nanostructures are of great importance for use in the LIBs especially as anodes. Nitrogen doping and the various ways in which that is achieved showed very good results. The doping of C-based structures with beryllium, boron, and the co-doping of nitrogen and sulfur gave a different view on the possibilities. The adsorption mechanism of lithium was discussed which gave us a theoretical viewpoint of the procedures that goes on inside the LIBs. Also, the effect of defective sites in graphene structures as well as doped graphene structures on Li adsorption shows that these enhance the lithiation and de-lithiation of Li ion. The heterostructures of graphene with other 2D materials show the many possibilities for experimentation to improve the anode

The authors are thankful to Higher Education Commission (HEC) of Pakistan for providing research funding under the Project No.: 6040/Federal/NRPU/R&D/ HEC/2016 and HEC/USAID for financial support under the Project No.: HEC/ R&D/PAKUS/2017/783. The author also thanks School of Natural Sciences (SNS) at National University of Science & Technology (NUST), Islamabad, Pakistan for

**262**

There are no conflicts of interest.
