Self-assembly of two-dimensional supramolecular as flame-retardant electrode for lithium-ion battery

Abstract

Owing to natural abundance, economic efficiency, and easy design of the molecular structure, organic polymer materials have caught much attention in the fields of electronics, separation, catalysis, and etc. However, low fire safety is the main obstacle for their applications. Herein, a novel phosphorus-rich and nitrogen-rich organic polymer material (MAPA) is prepared for the first time by supramolecular self-assembly with natural phytic acid as phosphorus precursor and melamine as nitrogen precursor. When MAPA is used as an anode for lithium-ion batteries (LIBs), it shows excellent specific capacity and stability. Specifically, at a current density of 0.1 A g−1 an initial capacity of 570 mA h g−1 and 397 mA h g−1 after 600 cycles are achieved, which is attributed to the abundant functional groups such as phosphate and π bonds of MAPA. Furthermore, the flame-retardant properties of MAPA are evaluated in two kinds of commonly used electrolytes, the ethylene carbonate and dimethyl carbonate (1: 1 vol, ECDC) for LIBs and the quasi-solid gel electrolyte of solid supercapacitor (polyvinyl alcohol, PVA). Both the ECDC/MAPA obtained through ultrasound sonication technology and the PVA/MAPA obtained through electrospinning technology exhibit excellent flame-retardant property. Notably, the peak heat release rate (pHRR) and total heat release (THR) values of ECDC/10% MAPA reduce to 31.2% and 44.8% of those for pure ECDC, respectively. And the pHRR and THR values of MAPA/15% PVA reduce to 57.4% and 75.6%, respectivly, and the char residues increases to 21% from 6%.