The classification of lithium battery failure and the failure reason is introduced

Source: 2020 - 03 - 25 14:05 hits: first lithium batteries fault classification and the reason of 1 lithium battery fault classification in order to avoid function attenuation and battery safety problems, to analyse the lithium battery is imperative. Lithium battery failure refers to the material for some specific reason leads to the deterioration of the battery function or dysfunction of running. Common lithium battery fault classification 2 the cause of the failure reasons of lithium-ion battery lithium battery failure can be divided into internal cause and external cause. Internal cause is mainly refers to the failure of the nature of the physical and chemical changes, dimensions can be traced back to the atomic and molecular scale, study the failure process of thermodynamics and dynamics of the change. External factors include shock, acupuncture, corrosion, high temperature fire, external factors, such as artificial damage. Lithium battery fault classification and the cause of the problem of lithium battery internal fault of 3. Lithium battery common faults and fault mechanism analysis capacity attenuation in the standard cycle life test failure, 500 cycle of discharge capacity shall be not less than 90% of the initial capacity. Or when the cycles of 1000 times, discharge capacity should not be less than 80% of the initial capacity '. If the standard cycle capacity fell sharply, belong to capacity attenuation. Battery capacity attenuation failure is rooted in the data, and the data of failure and battery manufacturing technology, the work environment is closely related to the objective factors. Statistically, the main reason for the failure has a positive electrode data structure failure, negative electrode appearance of SEI hypertrophy of synthesis and disintegration, electrolyte, set fluid corrosion, system trace impurities, etc. The structure of the positive electrode data failure: the data of the positive electrode structure failure including particle breakage, irreversible phase transition, data disorder, etc. In the process of charging and discharging, because jahn - Teller effect, the structure of the LiMn2O4 will be distorted, lead to particle breakage, electric contact failure between the particles. limn1。 5ni0. 5 data will have a phase transition 'm1 tetragonal crystal system - Cubic crystal system 'in the process of charging and discharging, although LiCoO2 data will lead to the company into the transition layer due to li li and release in the process of charging and discharging, this will constitute a hierarchical structure disorder and limit its ability. Negative data failure: graphite electrode failure occurs mainly in the surface of graphite, graphite surface react with the electrolyte, the consumption of solid electrolyte interface ( SEI) 。 Assume that excessive growth can lead to cut down the content of lithium ion battery internal system and lead to capacity attenuation. The failure of the silicon anode material is mainly due to its large volume contraction cycle function failure. The electrolyte failure: LiPF6 poor stability, simple synthesis, alternative Li + in the electrolyte content is lower. It is also simple to react with trace water in the electrolyte, formation of HF, form the corrosion inside the battery. Caused by a lack of air tightness, dissolution of electrolyte, electrolyte concentration and viscosity changes, resulting in a sharp drop in ion transport function. Failure: the collector fluid collector fluid corrosion, the collector fluid adhesion. The failure of HF electrolyte can produce corrosion, to the collector fluid producing conductive compounds, with poor cause ohmic contact increase or active material failure. In the process of charging and discharging, copper foil with low potential dissolution, deposition in positive electrode surface, known as' evolution of copper. Common methods of collecting fluid failure is a fluid and active material is not enough to lead to the separation between the force of active material, thus can't provide the battery capacity. Internal resistance increases lithium battery internal resistance increases along with the energy density of descent, voltage, power, battery failure problem such as thermogenesis. The main factors of lithium ion battery internal resistance increase is divided into the key data and battery using the environment.