**3. Conclusions**

Al-S batteries prepared based on S/HPCK cathode delivered a capacity of 1027 mA h g−1 at 0.2 A g−1 for 50 cycles and exhibited excellent cyclic ability 405 mA h g−1 at 1 A g−1 for 700 cycles due to large porous structure with high surface area by adding of carbon powder. The Al-Se battery based on MCFs material with pore size of 7.1 nm exhibited a good capacity of 366 mA h g−1. The chloroaluminate ion diffusivity greatly improved, which enhances the electrochemical behavior of Al-Se batteries. The rGO materials are introduced in the Al-Te batteries exhibited excellent cyclic ability and its initial capacity of 935.5 mA h g−1 and showed 467.5 mA h g−1 after 150 cycles with the Te loading of 70 wt% due to their excellent encapsulation.

The Interfacial layer of S@ spinel Ni-Co oxide double-shelled microspheres (NCO-HS) prepared under high sulfur loading exhibited minimum capacity fading rate of 0.045% per cycle over 800 cycles with high areal capacity of 6.3 mAh cm−2 and superior rate capability up to 5 C. As prepared capping layer of MTO-CNTs on surface of the sulfur cathode exhibited reversible capacity of 1212 mAh g−1 at the 0.2 C. The cycling stability of the device with the capping layer at 0.5 C rate still it retains a capacity of 577 mAh g−1 after 500 cycles with capacity decay rate of 0.07% per cycle, indicating a good cycling stability.

There is a gradual deterioration in all the compounds in the case of mixed cationic and anionic cyclic performance at a very low current density of 10 mA/g for 50 continuous cycles in terms of capacity fade. Cycling test of the 0.2 Fe substituted cathode done at 50 mA/g, reveals that the high rate cycling stability about 76% retention after 80 cycles. In the case of polysulfides on lithium deposition, the addition of Te exceeds 80% of its peak capacity for nearly 150 cycles and retains their cycling capacity without rapid drop until the electrolyte dryout nearly 300 cycles.

The developments of high-performance Se1-xSx cathodes such as NC@SWCNTs@ Se0.2S0.8 cathode exhibits good cycling stability (632 mA h g−1 at 0.2 A g−1 at 200 cycle)
