**5.6 Other applications**

It is well known that carbon materials are important materials for the preparation of various batteries. From ancient dry batteries to today's high-efficiency fuel cells, as well as new high-energy storage batteries being developed, pitch-based carbon materials are playing an increasingly important role. Mesophase pitch is an easily graphitizable carbonaceous precursor. After high-temperature heat treatment, its three-dimensional stack structure is very regular, and mesophase pitch can be transformed into a high-crystalline graphite. The necessary energy of intercalating lithium ions into the carbon layers is relatively low, and thus such material has a large lithium insertion depth and reversible capacity [44, 45], especially carbonaceous mesophase-derived coke after spheroidizing and coating treatments as shown in **Figure 23(a)** which can significantly improve the cycle stability and service life of the battery.

By the same token, using the easily graphitized mesophase pitch-derived carbon as a raw material, a large-sized graphene (or a few layers of graphene sheets) with uniform thickness and good transparency as shown in **Figure 23(b)** can be successfully prepared through a special technique (i.e., molten salt ion intercalation stripping), which can realize the size and thickness control of carbon layers. The preparation method seems to be very simple and easy to operate and thus will have a good prospect.

In addition to being used as a high-quality raw material for the above-mentioned carbon materials, carbonaceous mesophase can also be used to prepare some novel and value-added carbon materials such as miracle graphene [46], carbon quantum dots [47], good binder for high-performance magnesia carbon bricks [48], fluorinated pitch [49], etc.

**115**

*Preparation, Characterization, and Applications of Carbonaceous Mesophase: A Review*

In this chapter, the preparation, characterization, and applications of naphthalene-based carbonaceous mesophase are reviewed. With the continuous advancement of preparation techniques and characterization methods, the understanding of the molecular structure, molecular weight, molecular weight distribution, aggregation texture, and rheology property of mesophase liquid crystals will be deepened, and finally the comprehensive understanding of the carbonaceous mesophase (including the formation mechanism, molecular dynamic law and highefficiency control) from molecular and micro and macro scales could be realized, which will maximize the performance of carbonaceous mesophase-derived carbon products with desirable performance, multi-versatility, and high added value, thus to promote the theoretical foundation of carbonaceous mesophase and accelerate its

*Typical (a) SEM image of carbonaceous mesophase-derived spherical coke used as Li-ion battery anodes and* 

*(b) TEM image of carbonaceous mesophase-derived graphene with a relatively large size.*

The authors would like to thank professor Xuanke Li for his good suggestion and professional advice. This work was supported by the National Natural Science Foundation of China (Grant Nos. 91016003 and 51372177), the Hubei Provincial Department of Education Science Research Project (Grant No. Q20141104), the Key Laboratory of Hubei Province for Coal Conversion and New Carbon Materials (Grant No. WKDM201701), and the China Scholarship Council Fund (201808420114).

*DOI: http://dx.doi.org/10.5772/intechopen.88860*

**6. Conclusions**

**Figure 23.**

broad applications in various fields.

**Acknowledgements**

**Conflict of interest**

The authors declare no conflict of interest.

*Preparation, Characterization, and Applications of Carbonaceous Mesophase: A Review DOI: http://dx.doi.org/10.5772/intechopen.88860*

#### **Figure 23.**

*Liquid Crystals and Display Technology*

*(a) Optical photograph, (b) PLM micrograph, and (c) SEM image of unidirectional carbon/carbon composites reinforced by mesophase pitch-based carbon fibers using pyrolytic carbon as a "binder."*

*(a) Optical photograph, (b) PLM micrograph, and (c) SEM image of natural flake graphite-molded blocks* 

It is well known that carbon materials are important materials for the preparation of various batteries. From ancient dry batteries to today's high-efficiency fuel cells, as well as new high-energy storage batteries being developed, pitch-based carbon materials are playing an increasingly important role. Mesophase pitch is an easily graphitizable carbonaceous precursor. After high-temperature heat treatment, its three-dimensional stack structure is very regular, and mesophase pitch can be transformed into a high-crystalline graphite. The necessary energy of intercalating lithium ions into the carbon layers is relatively low, and thus such material has a large lithium insertion depth and reversible capacity [44, 45], especially carbonaceous mesophase-derived coke after spheroidizing and coating treatments as shown in **Figure 23(a)** which can significantly improve the cycle stability and service life of

By the same token, using the easily graphitized mesophase pitch-derived carbon as a raw material, a large-sized graphene (or a few layers of graphene sheets) with uniform thickness and good transparency as shown in **Figure 23(b)** can be successfully prepared through a special technique (i.e., molten salt ion intercalation stripping), which can realize the size and thickness control of carbon layers. The preparation method seems to be very simple and easy to operate and thus will have a

In addition to being used as a high-quality raw material for the above-mentioned carbon materials, carbonaceous mesophase can also be used to prepare some novel and value-added carbon materials such as miracle graphene [46], carbon quantum dots [47], good binder for high-performance magnesia carbon bricks [48], fluori-

*perpendicular to the hot-pressing direction using mesophase pitch as a binder.*

**Figure 21.**

**Figure 22.**

the battery.

good prospect.

nated pitch [49], etc.

**5.6 Other applications**

**114**

*Typical (a) SEM image of carbonaceous mesophase-derived spherical coke used as Li-ion battery anodes and (b) TEM image of carbonaceous mesophase-derived graphene with a relatively large size.*
