Pitch-Based Laminated Carbon Formed by Pressure Driving at Low Temperature as High-Capacity Anodes for Lithium Energy Storage Systems

Chemistry. 2020 Dec 9;26(69):16514-16520. doi: 10.1002/chem.202003493. Epub 2020 Nov 3.

Abstract

Pitch has been used to prepare electrodes by high-temperature heat treatments for supercapacitors, lithium-ion batteries, on account of its rich aromatic ring structure. Here, the toluene-soluble component of pitch is used to prepare a kind of laminated carbon. This was realized by a template-free synthesis at low temperature with the addition of pressure. The toluene-soluble component has a small molecular weight, which makes the thermal deformation ability stronger and then enhances the orientation of the carbon layer with the help of pressure. The prepared anode exhibits a splendid electrochemical performance compared with the traditional graphite anode. A high stable capacity of approximately 550 mAh g-1 at 50 mA g-1 , which is much higher than graphite (372 mAh g-1 ), is obtained. Also, when the current density is up to 2 A g-1 , the capacity is about 150 mAh g-1 . Surprisingly, it also delivers a superior cycling performance. And when used as the anode/cathode electrode for lithium-ion capacitors, a high energy density can be obtained. The present work offers an opportunity to utilize the pitch source in lithium energy storage with promising cycle life, high energy/power density, and low cost.

Keywords: coal tar pitch; high specific capacity; laminated carbon; low temperature; pressure driving.