▎ 摘　　要

NOVELTY - Lithium ion capacitor includes a positive electrode, a negative electrode, a separator, and an electrolyte. The material of the positive electrode includes lithium iron phosphate, electric double layer material, conductive agent and binder. The material of the negative electrode includes a carbon material with a crystal plane spacing d002 of at least 0.345 nanometer, a conductive agent and a binder. USE - Lithium ion capacitor for use in a lithium ion battery as an energy storage device (Claimed). ADVANTAGE - The lithium ion capacitor optimizes the positive and negative active substances of proper parameters, optimizes the material compounding and proportion, reduces the internal resistance of the current collector, preferably the diaphragm with high porosity and low air permeability, improves the conductivity of the electrolyte at normal temperature and low temperature, precisely controls the compacted density and surface resistance, improves the conductivity of the pole piece and the wetting quality of the electrolyte, reducing polarization, so as to improve the multiplying power performance and low temperature performance of the lithium iron phosphate lithium ion capacitor. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing a lithium ion capacitor, which involves superimposing a positive electrode, a negative electrode and a separator to form a superimposed cell, and injecting the superimposed cell into electrolyte, and then exhausting and sealing to obtain the lithium ion capacitor.