What ceramic materials are needed for lithium battery

With the continuous development of high-tech, advanced ceramic powders and products have become key materials and bottleneck materials in some high-tech fields. For example, in the lithium battery industry, some ceramic materials play an important role in the lithium battery production chain.

Some of these materials directly become electrodes and seperator materials. Some have become packaging materials, and some have become auxiliary materials in the lithium battery production process. The following video is the battery production introduction of TYCORUN ENERGY odm lithium ion battery pack manufacturer.

The market for these ceramic materials has also flourished because of lithium batteries. Today, let’s take a look at which ceramic materials are needed to produce a lithium battery.

Main ceramic materials of lithium battery seperator

Seperator is the part with the highest technical barrier among lithium-ion battery materials, and its cost ratio is second only to cathode materials, about 10% to 14%. In some high-end batteries, seperator cost ratio even reaches 20%.

At present, ceramic seperators can be divided into two types according to the preparation method, one is the traditional polyolefin seperator or non-woven film as the base film, a ceramic layer is covered on the basement membrane by bonding, hot pressing or grafting to form a ceramic composite membrane; The other is to mix nano and micro-level ceramic particles into organic materials to make a mixed slurry, and then stretch the slurry into a film or make a non-woven film.

With the popularity of motorcycle and electric vehicles, traditional polyolefin seperators cannot meet the requirements of high voltage battery in terms of high voltage resistance and high temperature performance. Seperator coating technology is adopted, and the low thermal conductivity of ceramics is used to prevent certain thermal runaway points in the battery from expanding to form an overall thermal runaway;

The structural properties of inorganic materials can improve the thermal shrinkage performance of the seperator, which has higher safety and high potential resistance. In addition, the ceramic coating is hydrophilic and has a better liquid absorption function for liquid electrolytes, which can also improve the uniformity of the internal current distribution of the lithium battery during charging and discharging. Currently, the most concerned lithium battery main ceramic materials are high-purity alumina, boehmite, etc. for battery seperator.

High-purity aluminum oxide

Aluminum oxide is a high-hardness compound with a melting point of 2054°C and a boiling point of 2980°C. It is an ionic crystal that can be ionized at high temperatures. As an inorganic substance, aluminum oxide has high thermal stability and chemical inertness, and is a good choice for battery seperator ceramic coatings.

The seperator ceramic material has high purity alumina

Its advantages are:

(1) Long cycle life. Reduce the mechanical micro-short circuit in the cycle process and effectively improve the cycle life;

(2) High magnification. High-purity nano-aluminum oxide can form a solid solution in lithium batteries, improving rate and cycle performance;

(3)High-purity nano-aluminum oxide also has very good thermal conductivity. When the battery temperature is too high, this material can conduct heat well, thus solving the problem of poor thermal conductivity of PP/PE materials;

(4) Good wettability. High-purity nano-aluminum oxide powder has good liquid absorption and liquid retention capabilities;

(5) High-purity nano-aluminum oxide material also has excellent flame retardancy. This is because the aluminum oxide material itself is a very good flame retardant, even if the temperature reaches the zero point of combustion, the good flame retardancy of the material will prevent large-scale combustion or even explosion;

(6) When the current is too large, it can block the current. With the continuous improvement of lithium-ion battery capacity, the energy stored inside is getting bigger and bigger, and the internal temperature will increase.

It is possible that the temperature is too high to melt the negative seperator and cause a short circuit

Boehmite

Boehmite (AlOOH) is the precursor of γ-Al2O3, with its unique chemical, optical and mechanical properties, it has been widely used in the fields of ceramic materials, composite materials, surface protection materials, optical materials, catalysts and carrier materials, semiconductor materials and coatings.

Application of boehmite lithium battery diaphragm coating

In addition to meeting the requirements of lithium batteries for seperators, boehmite has the following advantages compared with aluminum oxide::

(1) The hardness of boehmite is low, in the process of cutting and coating, it has little mechanical wear, and its cost is lower than that of high-purity aluminum oxide.

(2) Boehmite has high heat resistance temperature and good compatibility with organic matter.

(3) The specific gravity of boehmite is small, and the same weight can cover 25% more area than high-purity aluminum oxide.

(4) High coating smoothness and low internal resistance.

(5) Low energy consumption, and the production process is more environmentally friendly.

(6) The water absorption rate of boehmite is only half of that of high-purity aluminum oxide.

(7) The preparation of boehmite is simpler, unlike high-purity aluminum oxide, which has to go through a series of complicated processes such as calcination, crushing, and classification.

(6)The replacement of boehmite materials has no threshold for equipment and process replacement for seperator companies and battery companies, and the damage to seperator company equipment is small. Seperator companies also tend to cooperate with battery companies to speed up boehmite material verification and product verification.

Lithium battery cathode additive – Zirconia

The application of nano-composite zirconia products in the field of new energy is also expanding. More and more lithium battery designs start to use zirconia powder ceramic material as the cathode additive material to stabilize battery performance and increase cycle life. Let’s take lithium nickel cobalt manganese oxide (LiNi0.8Co0.1Mn0.1O2) cathode material as an example to see the effect of nano-zirconia on the performance of cathode materials.

The research found that the specific discharge capacity of the ZrO2-doped material is significantly higher than that of the original LiNi0.8Co0.1Mn0.1O2 material, this may be related to the smaller particle size of the ZrO2 doped material. The smaller the particle size, the easier the deintercalation of the material during the charge and discharge process, so the discharge specific capacity of the doped material increases.

As the charge and discharge progress, a certain amount of dopant ions Zr4+ may also migrate to the electrode surface and form a solid solution, structural collapse due to anisotropic structural changes during charge and discharge is prevented, while the solid solution also acts as a protective coating preventing cobalt from dissolving into the electrolyte. Therefore, the material structure becomes very stable during the phase transition during cycling, and the cycling stability is enhanced.

Other ceramic materials used for lithium batteries

Cordierite-mullite saggers are widely used in the field of lithium battery cathode materials because of their excellent thermal shock resistance and economical efficiency. The silicon carbide push plate is mainly composed of silicon oxide and silicon carbide. It is used in the push plate kiln for lithium battery cathode material and the calcined push plate kiln for inorganic powder. The application temperature is not high.

The main materials of ceramic rollers are: corundum, aluminum silicon, fused quartz and silicon carbide. In terms of lithium batteries, the role of the roller furnace is mainly to provide a closed space with an oxidizing atmosphere and heat in order to realize the sintering of the positive electrode raw materials of lithium-ion batteries.

In the lithium battery sealing link, a coin-sized electronic ceramic ring (scientific name “new power battery ceramic sealing connector”) is an important component in new energy electric vehicles, it is used to form a sealed conductive connection between the power battery cover plate and the pole.

In addition, some ceramic powders or products are used in the preparation or assembly of lithium batteries. In terms of lithium battery cathode, high-purity ultra-fine aluminum oxide ceramic materials can also be used as an additive material for the positive electrode of the battery to play the role of coating and doping.

In terms of lithium battery anode, it is understood that silicon carbide micropowder ceramic materials can be combined with graphite, carbon nanotubes, nano-titanium nitride, etc. to make lithium battery negative electrode materials, which can improve the capacity and service life of lithium batteries.

In short, with the continuous development of advanced technologies and materials, more ceramic materials may be applied to lithium batteries and even the entire new energy field in the future, and there may be more and more lithium ion battery company will have ceramic materials