The lithium ion battery capacity attenuation of shallow reason

Source: 2020 - 03 - 23 14:27 hits: a preliminary classification of lithium ion battery 1. According to lithium battery electrolyte, lithium ion battery can be divided into liquid lithium battery, 自由) And polymer lithium ion battery, 嘴唇) 。 Ii. According to the charging ways, can be divided into two categories, not charging and rechargeable. Iii. Square lithium batteries (lithium battery appearance: Such as commonly used cell phone batteries) And cylindrical lithium-ion battery ( Such as 18650, 18500) ; Four, lithium battery outsourcing data: aluminum lithium batteries, lithium batteries, soft package steel battery; Five, the lithium battery by the positive and negative data ( Additives) : lithium cobalt oxide ( LiCoO2) Batteries, lithium manganese acid ( LiMn2O4) Batteries, lithium iron phosphate battery, disposable lithium manganese oxide. The cause of the lithium ion battery capacity attenuation lithium ion battery is following the nickel cadmium battery and nickel metal hydride batteries of the fastest growing secondary battery. Its high energy features make it the future looks very bright. However, lithium ion battery is not perfect. The biggest problem is that the stability of the charging and discharging cycle. This article summary analysis the attenuation, the likely cause of the lithium ion battery capacity including overcharge, electrolyte differentiation and self-discharge. Reason 1:1 overcharging. Graphite anode overcharge response: when the battery overcharge lithium ion will simply accumulated in the cathode surface recovery and accumulation on the surface of the lithium ions in the cathode block lithium ion insertion. Discharge the causes involved in power decrease and the capacity loss of: ( 1) Recycled lithium reduction; ( 2) The accumulation of lithium metal and solvent and supporting electrolyte reaction; Li2CO3, LiF, or other products, ( 3) Lithium metal is formed between the cathode and clearance, may be a gap between the gap increased the resistance of the battery; Due to the nature of the lithium is very lively, easy to react with the electrolyte electrolyte and consumption. Charging speed, current density is too large, negative polarization is serious, lithium ion accumulation will be more obvious. This situation occurs only in positive active material that is associated with negative active material excess. However, in the case of high charge rate, even if the positive and negative active material share is normal, the accumulation of metallic lithium may also occur. 2, positive response to too much when the proportion of the positive active material and the negative active material too low, simple positive charge will occur. The positive charge causes loss of capacity is the main reason of the electrochemical inert material ( Such as Co3O4 and Mn2O3, etc. ) Attack damage the capacity balance between the electrodes, capacity loss is not reversible. ( 1) LiyCoO2LiyCoO2 - ( 1 - ) y / 3 [ Co3O4 + O2 ( g) ] + yLiCoO2 y < 0. 4 because does not exist in the process of the electrolyte differentiation compound reaction ( Such as the formation of H2O) And the accumulation of combustible gas, so the sealing the result of the lithium ion battery anode data is unthinkable. ( 2) - MnO2 lithium manganese oxide in addition to the lithium in full: lambda - MnO2→ Mn2O3+O2( g) 3. The oxidation of electrolyte overcharge when should pressure is greater than 4. 5 v, the electrolytic oxidation into insoluble substances ( Such as Li2Co3) And gas, hinder the lithium ion migration in the electrode pore capacity loss in the process of circulation.