In this era of exponential growth
in energy demand and its adverse
effect on global warming, electrochemical energy storage systems have
been a hot pursuit in both the scientific and industrial communities.
In this regard, supercapacitors, Li-ion batteries, and Li–S
batteries have evolved as the most plausible storage systems with
excellent commercial adaptations. Intending to get the best performance
from these systems, researchers all over the world have been engaging
to develop various new methods for the synthesis of advanced carbon
materials with a target of economical viability, abundance, low cost,
and ease of preparation. Among them, activated carbon has proven to
be an attractive electrode material due to its many advantageous properties
such as a large surface area, high pore density, good conductivity,
low cost, and good mechanical and chemical stability compared to other
alternatives, such as high-cost graphene, carbon nanotubes, Mxenes,
transition metal complexes, and conducting polymers. Among the numerous
synthetic and biological resources that are used for the synthesis
of activated carbon, coal/coal-like materials have found tremendous
importance in recent times due to their relative abundance, extremely
low cost, and excellent large-scale production possibilities. The
present review attempts to collect all the significant innovations
carried out for the use of cheap and economically viable coal-derived/-based
activated carbon and its composites in supercapacitors, Li-ion batteries,
and Li–S batteries and to critically evaluate their comparative
performances. The progress in advanced three-dimensional printing
technology for these energy storage applications is also discussed.
The highlight of this review is also to assess the challenges that
remain for the synthesis of high-performance electroactive-activated
carbon materials from coal-based resources as alternative electrode
materials, which would become promising candidates in the foreseeable
future.