Nitrogen rich, porous spherical carbon particle with the large surface area was synthesized by simple pyrolysis of the amorphous covalent organic framework. The obtained mesoporous spherical carbon particles with dilated interlayer distance (0.377 nm), large surface area (390 m g) and high level nitrogen doping (10.9%) offer eminent electrochemical performance as an anode for both lithium ion (LIBs) and sodium ion batteries (SIBs). In LIB applications, the synthesized material delivers an average reversible capacity of 820 mAh g after 100 cycles at 0.1 A g, superior rate capability of 410 and 305 mAh g at 4.0 and 8.0 A g respectively. In SIBs, the material shows the stable reversible capacity of about 238 mAh g for the studied 500 cycles at 0.5 A g. The rate and steady state cycling performance at high current densities are impressive, being as high as 165 mAh g even after 250 cycles at 2.0 A g.

A core–shell-type spinel LiMn2O4/carbon composite was synthesized by a simple and cost-effective mechanofusion method (dry particle coating) with a highly uniform coating.

Exploring electrochemically chapped graphite/graphene composites derived from the bulk carbon rod of the spent Zn/carbon primary cell is for the advanced high-capacity lithium-ion battery anode. It is found that the synthesized graphitic carbon has grain boundary defects with multilayered exfoliation. Such material exhibits an average specific capacity of 458 mA h g–1 at 0.2 C, which is higher than the theoretical specific capacity (372 mA h g–1) of graphite. The differential specific capacity calculations also show no significant difference in lithiation and delithiation potentials for the exfoliated sample at the low voltage. However, two additional plateaus have also been observed at ∼1.2 and 2.5 V, which confirms the formation of the LiC3 phase similar to lithiation of graphene. Hence, the superior lithiation ability and thecycling stability of defected graphite/graphene flakes may be useful for the sustainable development of next-generation high energy lithium-ion batteries. Also, waste recovery tends to reduce the risk of environmental pollution and the cost of raw materials.

Nickel-rich layered, mixed lithium transitionmetal oxides have been pursued as a propitious cathode material for the future-generation lithium-ion batteries due to their high energy density and low cost. Nevertheless, acute side reactions between Ni 4+ and carbonate electrolyte lead to poor cycling as well as rate performance, which limits their large-scale applications. Here, core−shell like Li-Ni 0.8 Co 0.15 Al 0.05 O 2 (NCA)−carbon composite synthesized by a solvent-free mechanofusion method is reported to solve this issue. Such a core−shell structure exhibits a splendid rate as well as stable cycling when compared to the physically blended NCA. In operando X-ray diffraction studies show that both materials experience anisotropic structural change, i.e., stacking c-axis undergoes a gradual expansion followed by an abrupt shrinkage; meanwhile, the a-axis contracts during the charging process and vice versa. Interestingly, the core−shell material displays a significantly high reversible capacity of 91% in the formation cycle at 0.1C and a retention of 84% at 0.5C after 250 cycles, whereas pristine NCA retains 71%. The robust mechanical force assisted dry coating obtained by the mechanofusion method shows improved electrochemical performance and demonstrates its practical feasibility.