Hard carbon anode energy storage

Is hard carbon a good anode material for sodium ion batteries?

Hard carbon (HC) is one of the most promising anode materials for sodium-ion batteries (SIBs) due to its suitable potential and high reversible capacity. At the same time, the correlation between carbon local structure and sodium-ion storage behavior is not clearly understood.

What is the reversible capacity of a hard carbon anode?

The reversible capacity of the hard carbon anode prepared by preoxidation could be increased by about 24 % to 274.2 mAh g –1 compared with the hard carbon anode without preoxidation. Different coals have distinct structural characteristics, resulting in different electrochemical properties for sodium ion storage .

How can a hard carbon anode reduce the efficiency of sodium-ion batteries?

Defects are inevitable in the hard carbon anode, which results in a large number of irreversible sodium ion sites and reduces the efficiency of sodium-ion batteries. The reduction of defects in the hard carbon anode can be achieved by changing the carbonization process conditions and introducing reducing agents.

What are the advantages of a hard carbon anode?

At high mass loading, the hard carbon anode demonstrates high power capacity (1.05 mAh cm −2 at 2 A g –1) and excellent cycling stability. Additionally, coupling different precursors can also combine their advantages to prepare high-performance hard carbon materials.

Is coal a good anode material for sodium ion batteries?

To date, coal-based hard carbon is a promising anode material for sodium-ion batteries due to its high storage capacity, appropriately low operating potential and relatively stable source. In addition, coal offers significant advantages in terms of cost, scale-up production and commercialization.

What is the reversible capacity of HC O anode?

The HC O anode displays a high reversible capacity of 352.9 mAh g -1 and ICE of 88.0 %. Hard carbon with abundant pore structure and suitable interface has become a promising anode for sodium-ion batteries. However, it is still a challenge to accurately regulate the hard carbon micropore structure and customize the appropriate interface.