Assembly of N- and P-functionalized carbon nanostructures derived from precursor-defined ternary copolymers for high-capacity lithium-ion batteries

Synthesis of new carbon nanostructures with tunable properties is vital for precisely regulating electrochemical performance in the wide applications. Herein, we report a novel approach for the oxidative polymerization of N- and P-bearing copolymers from the self-assembly of three different monomers (aniline, pyrrole, and phytic acid), and further prepare the respective carbon nanostructures with relatively consistent N dopant (6.2%–8.0%, atom) and varying P concentrations (0.4%–2.8%, atom) via controllable pyrolysis . The impacts of phytic acid addition on the compositional, structural, and morphological evolution of the copolymers and the resulting nanocarbons are well studied through a spectrum of characterizations including N 2 sorption , Fourier transform infrared spectroscopy, gel permeation chromatograph, scanning/transmission electron microscopy, and X-ray photoelectron spectroscopy. Gradual fragmentation of the nanosphere structures is evidenced with increasing addition of phytic acid, leading to different nanostructures from hollow nanospheres to 3D aggregates. Nanocarbons decorated with N and P dopants from pyrolysis are further utilized as anode materials in lithium-ion batteries, demonstrating enhanced electrochemical performance, i . e ., a reversible capacity of 380 mA·h·g −1 at 2 A·g −1 for NPC-0.5 during 200 cycles. The superior performance originates from the balanced porosity, and appropriate concentrations of P and pyrrolic N, thus pointing the direction for designing high-performance anode materials.