Long cycle life, low self-discharge carbon anode for Li-ion batteries with pores and dual-doping

Doping multielectronic elements into carbon materials is an effective method to improve their electrochemical performance, as it can not only improve the electrical conductivity of the material, but also capture more lithium ions when they are involved in Li-ion battery. Here, using flour as biomass carbon source, the chlorine/phosphorus dual-elements doped porous carbon materials are obtained by pyrolysis at 800 °C and hydrochloric acid treatment. The introduction of chlorine can significantly increase the capacity of carbon materials. Importantly, the hydrogen in mixed gas during heat treatment process can increase the degree of ordered carbon, which led to the improvement of material conductivity and the ability of lithium ions intercalation, further improving the cycling performance and rate performance. Under the current density of 0.2 A g⁻¹, it can remain 535.2 mAh g⁻¹ after 200 cycles. And after two months resting, the capacity only decline by 5.9%, and can still keep the stable cycling performance to 500 cycles. The simple and low cost design of carbon is a creative and promising candidate for anode materials of high performance Li-ion batteries.