The correct method of positive electrode material pre-lithiuming treatment of lithium problems?

ଲେଖକ: ଆଇଫ୍ଲୋପାୱାର - Mea Hoolako Uku Uku

This topic of lithium is already talking about the old life. We have made a simple summary of the current mainstream lithium resistance. In general, the metal Li powder and Li foil pen are used to carry out the negative tonifying technology, and it is also currently The tight way used by the power lithium-ion battery manufacturer, but safety issues and high costs are the problems that Metal Li lys.

In contrast, the positive height of the lithium process is good, does not change the existing process, but the technical maturity is low, and the relevant material manufacturers will launch the corresponding products. Positive electrode resolution In addition to adding a small amount of high capacity to the positive electrode system, there is a means to add excess Li elements from the positive electrode material synthesis, thereby storing excess LI in the positive material, in the first charge The excess LIs in the process can release the LI elements that supplement the negative electrode consumption, thereby achieving the purpose of improving the first efficiency. In two ways to add excess lithium in a positive electrode material, the first is that in the positive electrode material embedded by the electrochemical reaction, the positive electrode material is generally formed into a semi-battery, and the positive electrode material is paired.

The positive electrode material is then formed into a total battery in general negative electrode, thereby achieving lithium. This method is relatively simple, and it is also possible to control the amount embedded in Li, suitable for use in the laboratory, but the disadvantage is also very clear, the operation is more complicated, and there is no practical value in the actual machining. Another way is to add excess LI through chemical methods.

Although the technical difficulty is relatively high, do not add additional processes in battery processing, so more practical value. The concept of positive pre-lithium is from Germany Giuliogabrielli et al, Giuliogabrielli reported the first time by chemical method for the first time by chemical method, but Giuliogabrielli is desirable to synthesize Li1 + XNi0.5Mn1.

5O4 material (200mAh / g) The way lini0.5Mn1.5O4 material (147 mAh / g) is reversible capacity until 2017 Giuliogabrielli and other talents have discovered the potential of the Lithium-ion battery's first efficiency of lithium-ion batteries.

After the excess LI of the first charging process, Li1 + XNi0.5Mn1.5O4 material was converted to normal Li1 + XNi0.

5MN1.5O4 material and lini0.5Mn1.

5MN1.5O4 materials by controlling different ratios. The material is mixed, which can accurately control the ratio of Li, which completely compensates for the negative electrode in reversible capacity during the first charging process, which is also an innovation and breakthrough of the positive complement.

Giuliogabrielli synthesis of Li1 + XNi0.5Mn1.5O4 material is a chemical synthesis method, and in the synthesis of materials, the pen is newly added in the synthesis process, so it is more practical, which is effective to treat the first efficiency of SiOx lithium-ion batteries.

Method. However, excess LI is added to the positive material and form a stable structure, and ensure that the cycle performance of the material is not an impact, Xiaobian also appreciates all articles published by Giuliogabrielli, and has not seen Giuliogabrielli The method is used in other materials (eg, NCA and NCM materials), which also reflects the method from the side, not suitable for all positive electrode materials. Vanchiappanaravindan from India discovers that this approach can also be used on LIVPO4F materials.

The way Vanchiappanaravindan is a relatively simple electrochemical embedded approach, that is, the LIVPO4F is first into battery, which makes Li + embeds LIVPO4F materials. Li1.26VPO4F is formed, and then the battery is dissected, Li1.

26VPO4F, and the negative electrode material (A-Fe2O3 employed), using Li1.26VPO4F material to compensate for the A-Fe2O3 material in the first pair lithium process The non-reversible capacity (about 503mAh / g), greatly enhances the energy density of the whole battery. However, the Measures should first form a half-cell.

The use of electrochemical approach to embedding Li + into the positive material, so actually the actual use significance in the actual processing, so the subsequent will continue to explore how to pass the chemical way straight synthesis lithium excess LI1.26VPO4F material, realizing the positive tonic. The positive pre-lithium is an ideal method for treating the SiOx negative electrode and enhances the energy density of lithium ion battery, but to embed excess LI in the positive electrode and maintain a stable structure, facing a large challenge, therefore the current positive pre-lithium It is necessary to concentrate on the LIMN2O4 and Lini0.

5Mn1.5O4 materials that are concentrated in a spine-resistant structure, and the excess LI element can be used in NCA and NCM materials, and it does not affect the performance of NCA and NCM materials. Will have huge use value.

.