Encapsulating nanomaterials in carbon is one of the main
ways to
increase the cathode stability, but it is difficult to simultaneously
optimize the rate capacity and enhance durability derived from the
insufficient ion transport channels and deficient ion adsorption sites
that constipate the ion transport and pseudocapacitive reaction. Herein,
we develop the ligand-confined growth strategy to encapsulate the
nano-Na3V2(PO4)3 cathode
material in various carbon channels (microporous, mesoporous, and
macroporous) to discriminate the optimal carbon channels for synchronously
improving rate capacity and holding the high-rate cycle stability.
Benefiting from the unobstructed ion/charge transport channels and
flexible maskant created by the interconnected mesoporous carbon channels,
the prepared Na3V2(PO4)3 nanoparticles confined in mesoporous carbon channel (Mes-NVP/C)
achieve a discharge-specific capacity of 70 mAh g–1 even at the ultrahigh rate of 100 C, higher than those of the Na3V2(PO4)3 nanoparticles confined
in microporous and macroporous carbon channel (Micr-NVP/C and Macr-NVP/C),
respectively. Significantly, the capacity retention rate of Mes-NVP/C
after 5000 cycles at 20 C is as high as 90.48%, exceeding most of
the reported work. These findings hold great promise for traditional
cathode materials to synergistically realize fast charging ability
and long cycle life.