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6 Nanomaterials for Batteries
polyethylene (PE) or the combination of both EC and DMC; its main function is
to provide the transmission of Li
+ ion channel. The main component of lithium-ion
battery separator is (Fan et al. 2008) polyethylene or polypropylene or the compound
microporous membrane of the two; its function is to make the positive and negative
two electrodes separated and to avoid electrons passing through the battery’s inner
circuit, resulting in a short-circuit phenomenon, while not hindering the lithium ion
in which freedom through.
At present, cathode material is the core part of lithium-ion battery, and it is also
the main basis for distinguishing the different lithium-ion batteries, and accounts for
more than 40% costs of the total lithium battery. At the same time, the capacity of
cathode material limits the further development of lithium-ion battery. Therefore, as
a positive material, the following conditions must be met:
1. the material itself has a high Gibbs free energy, and there is a certain voltage
difference between the positive and negative materials to obtain higher output
voltage.
2. the material itself has a layered or similar pore like structure, which is beneficial
to the de-embedded Li
+ ions, and the structure will not change when it is inlaid.
3. the Li
+ ion should have a large diffusion coefficient in the internal structure of
the material and can withstand a high charge and discharge current.
4. the chemical and physical properties of the material are all stable, so that the
battery has good reversibility.
5. the material and the electrolyte coexist steadily without any reaction.
6. the material has good thermal stability, nontoxic, environmentally friendly, and
easy to prepare.
6.2.2.3 Cathode Material
At present, the capacity of the commercialized lithium-ion battery anode material
is over 300 mAh g
−1 (Li et al. 2010), and the specific capacity of the alloy anode
material has even exceeded 1000 mAh g
−1 (Lee et al. 2012) at the experimental
stage. However, the actual specific capacity of the corresponding commercial positive
material is less than 200 mAh g
−1 . Therefore, the key to further enhance the Li-storage
capacity of the whole lithium-ion battery is to study the higher Li-storage capacity
of the cathode material.
6 Nanomaterials for Batteries
polyethylene (PE) or the combination of both EC and DMC; its main function is
to provide the transmission of Li
+ ion channel. The main component of lithium-ion
battery separator is (Fan et al. 2008) polyethylene or polypropylene or the compound
microporous membrane of the two; its function is to make the positive and negative
two electrodes separated and to avoid electrons passing through the battery’s inner
circuit, resulting in a short-circuit phenomenon, while not hindering the lithium ion
in which freedom through.
At present, cathode material is the core part of lithium-ion battery, and it is also
the main basis for distinguishing the different lithium-ion batteries, and accounts for
more than 40% costs of the total lithium battery. At the same time, the capacity of
cathode material limits the further development of lithium-ion battery. Therefore, as
a positive material, the following conditions must be met:
1. the material itself has a high Gibbs free energy, and there is a certain voltage
difference between the positive and negative materials to obtain higher output
voltage.
2. the material itself has a layered or similar pore like structure, which is beneficial
to the de-embedded Li
+ ions, and the structure will not change when it is inlaid.
3. the Li
+ ion should have a large diffusion coefficient in the internal structure of
the material and can withstand a high charge and discharge current.
4. the chemical and physical properties of the material are all stable, so that the
battery has good reversibility.
5. the material and the electrolyte coexist steadily without any reaction.
6. the material has good thermal stability, nontoxic, environmentally friendly, and
easy to prepare.
6.2.2.3 Cathode Material
At present, the capacity of the commercialized lithium-ion battery anode material
is over 300 mAh g
−1 (Li et al. 2010), and the specific capacity of the alloy anode
material has even exceeded 1000 mAh g
−1 (Lee et al. 2012) at the experimental
stage. However, the actual specific capacity of the corresponding commercial positive
material is less than 200 mAh g
−1 . Therefore, the key to further enhance the Li-storage
capacity of the whole lithium-ion battery is to study the higher Li-storage capacity
of the cathode material.