**4. Conclusions**

In summary, the present data demonstrate a facile route for the synthesis of a nanocomposite consisting of HCS and metal oxide hybrid material. The synergistic effect of the components in FexOy/MnO2/HCS composite displays the enhancement of electrochemical properties in comparison to pristine HCS. The addition of MnO2 nanorods boosts the

reversible capacity and cycling performance. The discharge capacity of FexOy/MnO2/HCS is 1091 mAhg−<sup>1</sup> at 5 Ag<sup>−</sup>1, and the corresponding CE is as high as 98%. Therefore, the coexistence of two metal oxides stored in HCS resulted in design of composite that has the potential to be used as anode material for lithium-ion batteries with high cycling stability and boosted performance in comparison to the single metal oxide functionalization approach.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10.3 390/ma14226902/s1, Figure S1: TEM images of MnO2 rods on the HCS surface; Figure S2: Cycling stability at 100 mA/g.

**Author Contributions:** Conceptualization, E.M. and X.C.; methodology, K.W., W.K. and M.T.; writing—original draft preparation, K.W., X.C. and M.T.; writing—review and editing E.M. and W.K. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National Science Centre, Poland, within Beethoven UMO-2016/23/G/ST5/04200.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** All datasets generated for this study are included in the article.

**Conflicts of Interest:** The authors declare no conflict of interest.
