Lithium battery ternary cathode material

The ternary material "Ternary" international authoritative dictionary Merriam-webster defines "ternary" as "Having three elements, parts, or divisions or arranged in three ternary petals".

Therefore, “ternary material” refers to a whole composed of three chemical components (elements), components (simple substances and compounds) or parts (parts), including alloys, inorganic non-metallic materials, organic materials, and polymer composite materials widely used in mineral extraction, metal smelting, material processing, new energy and other industries.

Cathode material: The positive electrode material of lithium cobalt oxide battery is lithium cobaltate LiCoO2, and the ternary material is lithium nickel cobalt manganese oxide Li (NiCoMn)O2, a precursor product of ternary composite positive electrode material, which is nickel salt, cobalt salt and manganese. Salt is the raw material, and the ratio of nickel-cobalt-manganese can be adjusted according to actual needs. The battery with ternary material as positive electrode is safer than lithium cobalt oxide battery, but the platform is too low, which is used on mobile phones (the cut-off voltage of mobile phone is generally 3.4V). Left and right) there will be a clear feeling of insufficient capacity. In some cottage phones, there are already batteries with ternary materials, especially those with relatively high capacity. The capacity of lithium iron phosphate is low, and it is not suitable for the pursuit of high-capacity mobile phone batteries.

Applicable scope: power battery, small electric type

Product features: low cost, high gram capacity (>150mAh / g), working voltage matching with existing electrolyte (4.1V), good safety, platform relative to lithium cobaltate, lithium manganate is lower, but considering its pressure The comprehensive performance of real and gram capacity has a good application prospect. The common nickel-cobalt-manganese ratio is listed as 424/333/523/701515; the 1C-gram capacity is 145/147/155/165 for the sample test provided by Henan Thinking; the compaction used in the workshop is 3.4/3.5/3.3/3.2. The biggest obstacle to the use of mobile phones in China is the so-called discharge platform. The old view is that 4.2V is put into 3.6V time is the time for mobile phone work. In fact, many mobile phones are 3.3 or even 3.0V to shut down.

Japan and South Korea did not have a platform, compared with lithium cobalt oxide, the energy density of ternary needs to be improved, Japan mentioned the same degree as lithium cobalt oxide, that is, the Japanese ternary compaction is close to lithium cobalt oxide, the domestic still has gap. If compaction is brought up, the ternary will replace lithium cobalt oxide based on cost advantages and safety.

Anode material: A lithium ion battery anode material such as "Silicon Nanowire/Super-P/Polyaniline" and "Silicon Nanoparticles/Carbon Nanotubes/Polypyrrole" are ternary anode composite materials. In June 2013, Nanocommunication published an article entitled "Three-Dimensional Hierarchical Ternary Nanostructures for High-Performance Li-Ion Battery Anodes" [1], using synthetic P-polypyrrole to encapsulate silicon nanoparticles and using single-walled carbon nanotubes as an electrical enhancer. Improve electrochemical cycle stability and rate performance. In addition, its low cost, high efficiency and good industrial process compatibility have attracted widespread attention.

The drying technology of ternary materials is currently the most advanced in Japan. It uses rotary kiln equipment, but its metal pollution, product quality is affected, and microwave drying technology is better than rotary kiln technology, completely avoiding metal pollution, and It has the advantages of fast drying speed, dry processing in a few minutes, uniform drying, good quality, low drying temperature and low energy consumption. The equipment has a small footprint and is environmentally friendly!

Conductive coating

Surface treatment of battery conductive substrates with functional coatings is a breakthrough technological innovation. Carbon-coated aluminum foil/copper foil is a uniform and fine coating of aluminum nano-conductive graphite and carbon coated particles on the copper foil.

It provides excellent static conductivity and collects micro-current of active material, which can greatly reduce the contact resistance between the positive/negative electrode material and the current collector, and improve the adhesion between the two, reducing the bonding. The amount of agent used, in turn, results in a significant increase in the overall performance of the battery.

The coating is water-based (aqueous agent system) and oily (organic solvent system).

Advantages of carbon coated aluminum foil in lithium battery applications:

1. Suppress battery polarization, reduce thermal effects, and improve rate performance;

2. Reduce the internal resistance of the battery and significantly reduce the dynamic internal resistance increase of the cycle;

3. Improve consistency and increase battery cycle life;

4. Improve the adhesion between the active material and the current collector, and reduce the manufacturing cost of the pole piece;

5. Protect the current collector from corrosion by the electrolyte;

6. Improve the processing properties of lithium iron phosphate and lithium titanate materials.

7. Coating double-sided thickness: A section 4 ~ 6μm, B section 2 ~ 3μm.

Battery grade aluminum foil

On the basis of fully considering the thermal conductivity, electrical conductivity and mechanical strength of the aluminum foil, a special blank is used to manufacture the high-precision imported rolling mill with a wire plate type instrument and a Siemens control system in a clean dust-removing plant environment [2].

Features:

1. The aluminum foil rolling mill equipment is equipped with advanced AGC (Siemens thickness automatic control system) and AFC (Siemens automatic control system) system to achieve precise control of the plate type and thickness;

2. Select aluminum foil blanks, strictly control the hydrogen content of the blanks, the amount of non-metallic slag and grain size, and ensure the quality of the products from raw materials;

3. Using advanced online degreasing technology, on the basis of ensuring the mechanical strength of aluminum foil, to ensure the cleanliness of aluminum foil.

The ternary polymer lithium battery refers to a lithium battery using a nickel-cobalt-manganate (Li (NiCoMn) O2) ternary positive electrode material for the positive electrode material, and a ternary composite positive electrode material precursor product, which is a nickel salt, a cobalt salt, a manganese salt. As raw materials, the ratio of nickel-cobalt-manganese can be adjusted according to actual needs. The battery with ternary material as positive electrode is safer than lithium cobalt oxide battery, but the voltage is too low, which is used on mobile phones (the cut-off voltage of mobile phone is generally around 3.0V). ) There will be a noticeable lack of capacity.

The ternary polymer lithium battery refers to a lithium battery using a lithium nickel cobalt manganese ternary positive electrode material for the positive electrode material. There are many kinds of positive electrode materials for the lithium ion battery, mainly lithium cobaltate, lithium manganate, lithium nickelate, and ternary materials lithium iron phosphate and the like. At present, the ternary material battery replaces the widely used lithium cobalt oxide battery, and is widely used in the field of notebook batteries.

The material with relatively balanced capacity and safety has better cycle performance than normal lithium cobaltate. Its nominal voltage is only 3.5-3.6V in the early stage due to technical reasons. However, there are restrictions on the scope of use, but until now, with the formulation with continuous improvement and perfect structure, the nominal voltage of the battery has reached 3.7V, and the capacity has reached or exceeded the level of lithium cobalt oxide battery.

SANYO, PANASONIC, SONY, LG, and SAMSUNG have launched batteries for ternary materials. A considerable number of notebook battery lines have replaced the previous lithium cobalt oxide batteries with batteries of ternary materials, SANYO. In the SAMSUNG column battery, the production of lithium cobalt oxide batteries turned to ternary cells was completely discontinued. At present, most of the small high-power batteries at home and abroad use ternary cathode materials.

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