There are three main charge storage mechanisms

EDLC- electric double layer capacitance: physical adsorption of ions

characterized by square shaped CV (I = C dV/dt i.e., current proportional to scan rate)

Example: Carbon

Pseudocapacitance: surface redox reactions fast enough to produce nearly square shaped CV (current I is proportional to (scan rate)^x where x is close ~1

No peaks or very small redox peaks in CV with small (or no) peak separation

Example: MnO2

Faradaic (Battery-like) capacity: Sluggish redox reactions with current 'I' usually proportional to (scan rate)^0.5

Well separated redox peaks in CV

Example: Ni (OH)2; Li4Ti5O12

Materials with first two charge storage mechanisms fall under one category and are known as capacitive materials whereas materials with third mechanism are know as Faradaic/Battery materials

If you combine two different materials with capacitive mechanisms (EDLC or pseudocapacitance) then configuration is called Asymmetric Supercapacitor

example: carbon/carbon (two different carbon); C/MnO2

(Capacitive material| Capacitive material)

If you combine two materials; one capacitive type and one Battery type then it is called Hybrid Supercapacitor

Example: C/Ni(OH)2; C|Li4Ti5O12

(Capacitive material | Battery-like material)

It is unfortunate that the terms ‘‘asymmetric’’ and ‘‘hybrid’’ have been

used in such an ambiguous manner in the literature

Please read following papers:

1. Energy Storage in Nanomaterials – Capacitive, Pseudocapacitive, or Battery-like?

Article Energy Storage in Nanomaterials – Capacitive, Pseudocapaciti...

2. To Be or Not To Be Pseudocapacitive?

Journal of The Electrochemical Society, 162 (5) A5185-A5189 (2015)

3. An approach to classification and capacitance expressions in electrochemical capacitors technology

Phys. Chem. Chem. Phys., 2015, 17, 1084--1092

Hope this information helps.

AS

Supercapacitors store energy in purely electrostatic form. There are two types: the double-layer supercapacitors are based purely on the surface double layer, while in the pseudocapacitors the charge is distributed evenly across the electrode volume (in the most typical case metal ions are partially oxidized, so the electrode is charged positively).

In the battery-type electrode the energy is stored predominantly in the chemical form. The contribution of the double layer is very small and normally undesirable.

Main difference between two types is that in the supercapacitors only electrons move during charge and discharge while in the batteries ions also move. This results in much lower available charge/discharge rate in case of batteries.

Asymmetric SCs incorporate one EDLC electrode and one PC electrode. While the hybrid SC has one capacitor type electrode and one battery type electrode. Please read the following paper for clarification. I hope it helps.

Asymmetric SC are used to boost the operating voltage range (and hence its energy and power density) and to combine the different capacitive nature of the two dissimilar electrodes to improve its overall performance. Hybrid devices are used to get the combined effect of battery and supercapacitors ie. high power density and high energy density outcome in a single device. Please go through the following book for clear understanding of battery type, EDLC type and pseudocapacitive electrodes:

Electrochemical supercapacitors: scientific fundamentals and technological applications

https://books.google.co.in/books?hl=en&lr=&id=zCblBwAAQBAJ&oi=fnd&pg=PA1&dq=electrochemical+supercapacitors+scientific+fundamentals&ots=b9jv9bSzqx&sig=kD-1hW4Cms4GTxfB6uccKnrWpIY

The differences between asymmetric supercapacitors and hybrid battery supercapacitors were quite well exposed above, for the last decade(s). More recently, that older contrast is relaxing, due to the progress of the (nano)materials for electrodes and their devices, for both groups. So, the duty cycle (say for a daily use, etc.) of the electrodes (nanomaterials) and the devices will push the old limits; also, it will emerge newer reviews, beyond the bounds of the old considerations[1].

1. Storage Wars: Batteries vs. Supercapacitors http://berc.berkeley.edu/storage-wars-batteries-vs-supercapacitors/

Thank you all

@ Poonam Sundriyal : Thank you so . I go through the text you have suggested me.

@ Syeda Wishal Bokhari : Thank you. I have a problem in download the link you sent. If you don't mine can you please resend it?

@ Arunkumar Prabhakaran Shyma :

Thank you

Actually both are same. In both cases, one electrode is edlc type and the other is pseudocapacitive or battery type. I both cases, the main motivation is to increase the energy density by elevating the working voltage without reducing the power density significantly. However, assymatric term is mostly used for the systems using aquous electrolyte and hybrid term is used for the systems using organic Li or Na based electrolyte.

Dhrubajyoti Bhattacharjya thanks for great discussions, dear sir can you elabrate reg aq,non aq for ASC and Hybrid suits respectively? any reason behind assymatric term is mostly used for the systems using aquous electrolyte and hybrid term is used for the systems using organic Li or Na based electrolyte.

thanks advance

There are three main charge storage mechanisms

EDLC- electric double layer capacitance: physical adsorption of ions

characterized by square shaped CV (I = C dV/dt i.e., current proportional to scan rate)

Example: Carbon

Pseudocapacitance: surface redox reactions fast enough to produce nearly square shaped CV (current I is proportional to (scan rate)^x where x is close ~1

No peaks or very small redox peaks in CV with small (or no) peak separation

Example: MnO2

Faradaic (Battery-like) capacity: Sluggish redox reactions with current 'I' usually proportional to (scan rate)^0.5

Well separated redox peaks in CV

Example: Ni (OH)2; Li4Ti5O12

Materials with first two charge storage mechanisms fall under one category and are known as capacitive materials whereas materials with third mechanism are know as Faradaic/Battery materials

If you combine two different materials with capacitive mechanisms (EDLC or pseudocapacitance) then configuration is called Asymmetric Supercapacitor

example: carbon/carbon (two different carbon); C/MnO2

(Capacitive material| Capacitive material)

If you combine two materials; one capacitive type and one Battery type then it is called Hybrid Supercapacitor

Example: C/Ni(OH)2; C|Li4Ti5O12

(Capacitive material | Battery-like material)

It is unfortunate that the terms ‘‘asymmetric’’ and ‘‘hybrid’’ have been

used in such an ambiguous manner in the literature

Please read following papers:

1. Energy Storage in Nanomaterials – Capacitive, Pseudocapacitive, or Battery-like?

Article Energy Storage in Nanomaterials – Capacitive, Pseudocapaciti...

2. To Be or Not To Be Pseudocapacitive?

Journal of The Electrochemical Society, 162 (5) A5185-A5189 (2015)

3. An approach to classification and capacitance expressions in electrochemical capacitors technology

Phys. Chem. Chem. Phys., 2015, 17, 1084--1092

Hope this information helps.

AS