The increasing demand for electrical energy storage makes
it essential
to explore alternative battery chemistries that overcome the energy-density
limitations of the current state-of-the-art lithium-ion batteries.
In this scenario, lithium–sulfur batteries (LSBs) stand out
due to the low cost, high theoretical capacity, and sustainability
of sulfur. However, this battery technology presents several intrinsic
limitations that need to be addressed in order to definitively achieve
its commercialization. Herein, we report the fruitfulness of three
different formulations using well-selected functional carbonaceous
additives for sulfur cathode development, an in-house synthesized
graphene-based porous carbon (ResFArGO), and a mixture of commercially
available conductive carbons (CAs), as a facile and scalable strategy
for the development of high-performing LSBs. The additives clearly
improve the electrochemical properties of the sulfur electrodes due
to an electronic conductivity enhancement, leading to an outstanding
C-rate response with a remarkable capacity of 2 mA h cm
–2
at 1C and superb capacities of 4.3, 4.0, and 3.6 mA h cm
–2
at C/10 for ResFArGO
10
, ResFArGO
5
, and CAs,
respectively. Moreover, in the case of ResFArGO, the presence of oxygen
functional groups enables the development of compact high sulfur loading
cathodes (>4 mg
S
cm
–2
) with a great
ability
to trap the soluble lithium polysulfides. Notably, the scalability
of our system was further demonstrated by the assembly of prototype
pouch cells delivering excellent capacities of 90 mA h (ResFArGO
10
cell) and 70 mA h (ResFArGO
5
and CAs cell) at
C/10.