Monolayer Tungsten Disulfide Helps Evolution of Lithium Iron Phosphate Batteries

With the boom of new energy vehicles, more and more researchers are devoting themselves to the research of new energy batteries with high performance. At present, lithium-ion batteries have become the most basic battery materials because of their high energy density, long service life and no pollution to the environment. However, cathode materials are becoming the main bottleneck in the industrialization of lithium-ion batteries.

In the traditional production process of lithium iron phosphate, ion doping and simple carbon coating technology are mostly used. LiFePO₄ can not show good rate and cycle performance because of the incomplete carbon coating and the lack of conductive network connection between the coated lithium iron phosphate particles. With the development of new materials research, this Bug has been cracked. The key to cracking is the magic two-dimensional material, nano-single-layer tungsten disulfide.

In the process of formation of lithium iron manganese phosphate from lithium iron phosphate and lithium manganese oxide, researchers formed layered lithium iron manganese phosphate-tungsten disulfide nanosheet lithium battery cathode material by inducing layered structure of lithium manganese oxide and two-dimensional structure of tungsten disulfide nanosheet. This is the upgraded version 2.0 of lithium iron phosphate cathode material. The scheme has applied for patent.

Ferromanganese lithium phosphate-tungsten disulfide nanosheet lithium battery cathode material was used for lithium battery cathode material. The current discharge specific capacity of the battery reached 144 mAh/g at room temperature and 125 mAh/g at - 20 ~℃ through the test of assembled batteries. The specific capacity of current discharge is 115 mAh/g at 120 ℃, which has excellent high and low temperature stability and endurance.

The main factors to improve the performance are: two-dimensional tungsten disulfide nanosheet layered structure provides short-distance open channel for lithium ion intercalation deblocking. It has high conductivity, excellent resistance to high and low temperatures, high capacitance density, and can effectively buffer the volume expansion of battery structure, improve cycle stability and high efficiency. At the same time, tungsten disulfide was introduced into lithium iron phosphate by lithium manganese oxide, which ensured the layer structure of disulfide and only weaker van der Waals connection between the layers of tungsten disulfide. The existence of nano-scale single layer and multi-layer promoted the lithium storage performance, increased the thermodynamic stability of lithium batteries, and stabilized the charging and discharging cycle structure for many times.

Perhaps the lithium iron phosphate batteries that many experts see as worthless still have a lot of room for improvement, but they haven't found.

• < Prev
• Next >