Power Density vs. Energy Density

Supercapacitors and batteries are two energy storage devices. In the Supercapacitors, we can achieve *High Power Density* while in the case of Batteries, we can achieve *High Energy Density*.
If we can achieve both high *POWER DENSITY* as WELL as high *ENERGY DENSITY* then we can solve the BIG problem.

This is a clear *research gap* or *Problem Statement* for your PhD or MS research and you can choose this topic.

Let me explain here, how to write Problem Statemen for your PhD Study, for your research Proposal?

Every research whether it is PhD, MS or any faculty or even industrial people conducting research, it is always *starts with identifying a problem* which is usually an existing gap in your field of study.

Once you have the problem or gap, then the next step is to craft a statement of the problem that captures this issue and how you plan to resolve it. A statement of problem forms the basis of every systematic investigation.

A “problem statement” is basically a statement of current issue that required immediate action in order to enhance the scenario.

Keep one thing in mind that there there may be several solutions to the existing problem or research gap, but that is not the concern of the problem statement. Its main purpose is to summarize the current information regarding the current *issue* and where a lack of knowledge may be presenting a problem that needs to be investigated.
The following points must include while writing your Statement for a problem (Problem Statement):

1. Explain the problem (issue or gap) and state why it matters.
2. Give sufficient references (Old and latest)

See how I wrote my Problem statement when I was a PhD student during 2013 to 2016.

*Problem Statement* :

Photoanode is the heart of a solar cell. A desirable photoanode should have (i) high specific surface area to anchor large amount of dye, (ii) a suitable morphology for electron diffusion, electrolyte percolation and superior light harvesting, (iii) a favorable CB alignment with most of the dye molecule and (iv) high electron conductivity and mobility to improve charge collection in the device (Zhang and Cao, 2011).

Till date, various metal oxide have been employed as a photoanode ; however, none of them combine all these required features in a single material. TiO2, the most successful photoanode material, is characterized by high specific surface area (~150 m2/g) and suitable conduction band alignment with the most commercial ruthenium based dyes, however, it is characterized by low electron mobility (less than 1 cm2 V–1 s–1), which results in inferior charge collection. On the other hand, Although SnO2 offers high electron mobility (~250 cm2 V–1 s–1) (Elumalai et al., 2012), its photovoltaic (PV) performance is limited due to a mismatch in band alignment with respect to the most successful dyes and low specific surface area because of its low IEP (at pH ~6-7) (Liu et al., 2012, Parks, 1965). Therefore, innovative approaches are required to improve the performance of the photoanode by judiciously combining the favorable properties of the above two materials.

*Look, how I cited the literature and highlighted the issue exist with the material TiO2 in the field*.

[vipingujjar]

Can u explain me energy density and powerr density of battery with mathematical formulas

[prajaktadange]

agar power kam stroage wali battery jayda power deti he then why we used high energy storage capacity battery

[frankdimeglio]

Energy density equals inertia/inertial resistance multiplied times acceleration, thereby deriving F=ma AND E=mc² on balance.

By Frank DiMeglio