Dual carbon decorated Na₃TiMn(PO₄)₃ as an advanced cathode for sodium-ion batteries

Na super ionic conductor (NASICON)-type Na₃V₂(PO₄)₃ (NVP) is a high-energy sodium-ion battery material for sodium-ion batteries (NIBs), which has a high theoretical specific capacity, structural stability, and high safety performance. However, in order to promote its practical applications, it is imperative to replace vanadium with other low-cost and rich elements on earth. Therefore, NASICON-Na₃TiMn(PO₄)₃ (NTMP) is more attractive due to its higher voltage platform and lower toxicity. However, its low electrical conductivity, unsatisfactory rate performance, and cycle life limit its practical application. Herein, the feasibility to realize advanced rate capability and long durability through dual carbon decoration strategy that in situ embedding single-walled carbon nanotubes (SWCNT) into the bulk of Na₃TiMn(PO₄)₃@C is reported. The elaborately designed Na₃TiMn(PO₄)₃@C@SWCNT can deliver an initial charge capacity of 112 mA h g⁻¹ at a current rate of 0.1 C with a long durability over 1000 cycles at 2 C. This progress can be benefited from the improvement of the electrical conductivity of the materials brought by the cross-linked conductive network and the robust structure.