Lithium battery anode materials

The difference between lithium ion batteries compared and other battery

Compared with nickel metal hydride batteries, lithium ion battery charging and discharging voltage is higher, is about 3 times of Ni-Mh batteries, 3.7 V, and Ni-Mh battery charging and discharging voltage of 1.2 V.And compared to lithium batteries, both has the high volume energy and mass specific energy, but, in contrast, the stability of the lithium ion battery is better than lithium battery.For past lead-acid batteries, nickel cadmium battery, on the performance and stability than the current widely used lithium ion battery, also gradually replaced by a lithium-ion battery, fuel cell, etc.In addition, the volume of lithium ion battery is energy and mass is higher than energy than Ni-Mh batteries, on the working principle of the lithium ion battery is different from other batteries, for example, in lead-acid battery system, reactant is electrolyte, for the lithium ion battery, actually passed on between the positive cathode electrolyte, anode with the positive electrode is embedded materials, electrolyte between the positive negative transfer easily, therefore, lithium ion battery has a title, called "swing" battery.

The working principle of lithium-ion batteries

The working principle of lithium-ion battery is relatively simple, discharging, will break out part of the lithium ion in anode materials, into the electrolyte solution, and will have the same amount of lithium ion in the electrolyte embedded in the anode material, in the external circuit, the same time, electrons can flow from cathode to anode, with load for power supply, to provide energy.Lithium-ion batteries can be reversible process, this happens in an electric current or voltage on the cathode when loading.

The characteristics of the lithium ion battery cathode material

In lithium ion batteries is put forward for the first time and, for the anode materials research has been that a variety of low cost, good performance of new anode materials have been widely studied and discussed, as lithium ion battery cathode material, it must meet some requirements are: (1) easy to synthesis and lower cost;(2) less polluting to the environment;(3) when in contact with the electrolyte strong stability;(4) need to be strong conductive ability;(5) when the lithium ions in the electrolyte, embedded in the anode material and out when you can quickly react with the lithium ions;6. Must be able to with lithium ion reversible chemical reaction;7) must be able to produce REDOX reaction, containing transition metal elements.Meet the above requirements, to design the new anode materials also need to consider is the embedded battery system dynamic performance and thermodynamic performance.And for the morphology of the anode material and structure is also a consideration in design.

The influence of particle size on the anode material electrochemical performance

Material the diameter of the particle size, density, morphology and distribution dynamics have great influence to the battery positive electrode, stability in the cell, it plays an important role in the electrochemical properties, for example, spherical grain together to form a single spinel spherical grain, this will strengthen the cycle of the battery performance, grain diameter smaller chemical reaction can be more quickly, because the ions and electrons in the material diffusion path would decrease with the particle diameter and shortened, but the particle size is too small also have corresponding faults, such as low tap density can cause low energy density, low thermal stability, react when the electrolyte, the reactivity is reduced.In continuous research analysis, all kinds of synthesis methods of synthetic materials of different size particles, particle size and morphology will be the performance of lithium ion batteries is more superior.

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