Showing posts with label portable solar power generator. Show all posts
Showing posts with label portable solar power generator. Show all posts

Wednesday, 26 October 2016

Several Reasons of Lithium Battery System Fires

Security is the lifeblood of child battery, the lifepo4 48v system from the inside out cause of the fire in recent thinking and analysis, this is considered a major reason for the layers to push forward, then consider the previous and future accidents put to match then the future of an accident PPM (parts per million) based on the actual design of each model speculation. Hereinafter all manufacturers names are removed, does not explore this topic for any enterprise, not judge.

It is assumed from a single problem, and then extended to the global dimension of the experiment, it can be seen:

Analysis of the whole system just to match the battery fire this extreme event occurs, we segment the contents from mechanical abuse, battery system design basis is to focus on in a relatively safe position of the vehicle, to prevent problems in the course of the vehicle the whole mechanical design of course is a lot to do experiments security content acupuncture, extrusion, etc., but in fact the problem caused by the mechanical abuse but easily become a problem.

In Tesla's two accidents as an example:

Lithium ion Battery Explosion

1. On fire in Smyrna, Tennessee, this car electric cars rushed to drop the road trailer hitch, the fire broke out after the collision chassis.

2. When the driver hit the turn, and through the wall of a cement eventually hit a tree and stopped the fire.

3. In Seattle, the owner called and hit a metal fragments, so he left the highway. After the failure of the car, he smelled the smell of burning, fire burning vehicle at this time.

This mechanical design also appears on a simple structure in the periphery of the bottom cover and consider additional protection, you can get immediate results.

We make things happen this year, the manufacturers removed, you can then think about a car on fire outside the cell or battery? A large part of the load cell is outside the peripheral portion of the cable overheating lit things some more.

Here we can be divided into three basic, because the nature of fire:

Released in accordance with the design intent and outside the combustion heat within the battery, 

1. The combustible gas inside the battery release ignition

2. Flammable liquid inside the battery release + Flash point: here including electrolyte leakage and coolant leaks in two parts.

We can release heat energy battery systems to consider:

1. Battery Pack or Battery Cell Overcharge

Overcharge release of thermal energy in general is indeed more common reason, the storage battery pack of solar powered portable generator level thermal runaway event, can be broken down into more down the battery (modules monomer overcharge), evaporated electrolyte battery overcharge and overheating, as well as It is the battery remaining capacity (SOC) calculation error caused by over-charging, high SOC state, not in accordance with energy recovery protection cause, and the charging control program stuck due to overcharging.

2. A Person Short Circuit Overcurrent Heat Release

Lithium Battery Explosion

Battery pack high voltage circuit failure cause a short circuit, distributing heat. The main battery pack is an internal short circuit and external short circuit, causing the conductors and connectors overheating, caused by overheating of the monomer subsequent thermal event, is further broken down to be broken down into short-circuit caused by overheating of the module components. Eg short circuit module level, a short circuit within the battery pack, the external corrosion / conductive liquid into a short circuit caused.

3. High-impedance Connection of Heat

Fault battery pack high-voltage circuits, resulting in high resistance appearing at the position charging and discharging circuit, the current rise in the temperature of the high resistance point that could cause a fire and subsequent heat adjacent material spread. Trunk junction poor contact, corrosion caused by heat.

4. The Internal Resistance of The Battery Overheating and Internal Promotion

Monomers to produce a combustible gas exhaust, followed by a heat source (arc monomer thermal runaway) lead to the battery system, surplus heat. Monomeric single point of failure as defined thermal runaway experiment can be considered a single monomer extended to the whole aspect, in the given conditions, each battery pack for portable solar power generator will achieve record correspondent, some reference to the role, but the experimental conditions and the occurrence of failure is not It may be completely consistent.

The article comes from

Storage Batteries Made Significant Breakthrough

High-performance chemical storage batteries and portable solar power generator power plant key technology research, supported by high energy density, low-cost new supercapacitor key technologies , long-life lithium manganese battery energy storage system and key technology demonstration and other topics are significant progress was made, it has recently passed the technical acceptance.

Portable Solar Generators
New Super Capacitor

In the "new super capacitor", the preparation of technical bottleneck breakthrough high energy density and long life high power density supercapacitors portable solar power generator developed porous graphene, high voltage electrolyte salt and electrolyte, separator and other cellulosic materials, the development of dry preparing an electrode film test technology, breaking the (3.0V/12000F) supercapacitor industrialization of core technologies, products can be recovered in the machinery, rail vehicles supercapacitor respect at home and abroad to obtain applications. From domestic materials, devices integrated into the system formed in the super capacitor core technology system, changing the super capacitor during the Eleventh Five by the monopoly of foreign products.

Long-life Lithium Manganese Battery Energy Storage System

In the "long-life lithium manganese battery energy storage system", the industrialization of key technologies mastered the low-cost long-life lithium-ion energy storage system, launched a layered lithium manganese oxide, lithium manganese oxide single crystal surface coating, aluminum, cobalt Study co-doped material, a hard carbon anode material asphalt and resins derived function of the electrolyte studies, as well as single cells, modules and energy storage system of lithium manganese oxide cathode, single life expectancy has more than 3,000 times, some 6,000 times. Completed the development of two sets of 50kW / 100kWh level layered lithium manganese oxide / hard carbon lithium-ion battery energy storage system and the demonstration run, portable solar power generator is the first in the world; while the development of energy storage 20kWh solar home systems, 3kWh standby emergency power demonstration applications.

All-solid-state Lithium-ion Storage Battery

In the "all-solid lithium-ion storage battery", the successful development of high conductivity Li2S-P2S5 binary system and Li2S-GeS2-P2S5 ternary solid electrolyte mastered the system preparation Li2S-P2S5 glass-ceramic solid electrolyte material preparation method, the amorphous precursor made great breakthrough to achieve a stable production of high efficiency.

It has now achieved kg capacity sulfide solid electrolyte prepared. Development of the high nickel component layered cathode material having a core-shell structure and composition gradient. With the above binary sulfide solid electrolyte and cathode, developed capacity of 4.0Ah and 8.0Ah solid-state lithium batteries, the number of cycles at room temperature reached 500 times , and optimized assembly process proposed large-scale all-solid-state lifepo4 battery in soft packages solar power portable generator, promoted the industrialization process of all-solid lithium-ion battery.
self balancing scooter battery
New LifePo4 Batteries Chemical Energy Storage

In the "new type of lithium sulfur battery chemical energy storage", the development of high-energy density lifePo4 batteries technology preparation, development of 35Ah lithium-sulfur battery specific energy 566Wh / kg (25 ℃ test), reached the world advanced level. 1kWh initial development of lithium-sulfur batteries and large-capacity 12kWh llifePo4 batteries, solar power portable generator achieved its coupling power demonstration. Using elemental sulfur, high-capacity lithium-sulfur batteries and battery technology products have the potential when used as a long-endurance UAV airborne energy systems and other areas of application prospects.

Low-cost Lithium Titanate Energy Storage Lithium-ion Battery

In the "low-cost lithium titanate energy storage lithium-ion battery", the amount of material to get through the low-cost production, long life and high consistency and battery modules, portable solar power generator plant demonstration and promotion of the whole industry chain, to build a solar power portable generator system based on lithium titanate anode material demonstration of mobile storage devices, optical storage demonstration was 0.5MWh / 1MW lithium titanate energy storage power station, laid the foundation for lithium titanate energy storage applications.

To some extent, to meet the renewable energy and smart grid scale energy storage needs, and promote the orderly development of wind, solar powered portable generator and rational allocation of resources, improve the intermittent new energy grid technology, energy storage batteries for China material - batteries - integration - demonstration chain provides a more complete technical support system, building industry internationally competitive platform for future sustainable development of the industry and promote the development of China's storage industry, to enhance China's energy can strategic position of sustainable development, broad market prospects.

The article comes from