Rational design of dual catalysts towards efficient polysulfides conversion for high performance Li–S batteries

Abstract

Lithium-sulfur batteries are promising alternatives to lithium-ion batteries due to their high theoretical capacity and high energy density. However, severe active materials losing and capacity decay caused by shuttle effect restrict its practical application. Inspired by bipolar magnet, here we proposed dual catalysts embedded in nitrogen-doped carbon with different polar sites towards efficient lithium polysulfides conversion. The dual catalysts are composed of interlacing metal Co and Eu2O3 particles, in which the electronegative O2− in Eu2O3 and Co metal sites synergistically accelerate intermediates conversion. With this rational design, the cathode delivered an areal capacity of about 2.6 mAh cm−2 at the current rate of 1C during 100 cycles with the sulfur areal loading of 4.2 mg cm−2. Furthermore, the cathode could deliver a reversible capacity over 1000 mAh g−1 at 0.5C, and performed an excellent rate and cycling stability.