Effect of Ni content in NixMn1-xCO3 (x = 0, 0.20, 0.25, 0.33) submicrospheres on the performances of rechargeable lithium ion batteries

To compound with conductive agents is the common strategy to address the low electric conductivity of redox conversion type anode materials; however, it brings on the complex techniques and thus increases the practical cost. This paper reports a less efficiency-cost method through partial element substitution which can significantly enhance the electric conductivity of the host materials. Specifically, partial Ni substitution into MnCO3 with different x values, corresponding to NixMn1-xCO3 porous submicrospheres (x = 0, 0.2, 0.25, 0.33), were fabricated through one-pot solvothermal route and tested as anode materials for lithium ion batteries (LIBs). The substitution of Ni in the composites mainly serves as the following objectives: increasing the electric conductivity and improving the structural integrity. By comparison, the NixMn1-xCO3 sample at x = 0.25 value shows the optimal electrochemical behaviors: it delivers specific capacities of 709 mAh g−1 for 500th cycle at a high rate of 1.0 A g−1, and 549 mAh g−1 for 1000th cycle at 2.0 A g−1; more impressively, it also shows an excellent rate performance, exhibiting a 509 mAh g−1 at 5.0 A g−1 during the rate capability testing. These results demonstrated a cost-efficient way to ameliorate conversion-type negative electrode materials with high capacity and long life-span in LIBs.