Tuesday, 11 October 2016

What is Solar Energy Generation System

Solar power generation system, also known as solar energy storage system, solar energy is converted to electrical energy through the solar charge controller to power the load, while to the battery pack.



Introduction

Solar power generation systems, also known as solar power systems, solar energy is converted to electrical energy through the solar charge controller to power the load, while giving the lifepo4 battery pack; in the absence of sunlight through the solar charge controller from the battery to the DC load power supply, but also the battery directly to the individual inverter power supply, through a separate inverter is inverted into AC power to the AC load.

System Principle

Sun light in the semiconductor p-n junction, forming a new hole - electron pairs, under the action of p-n junction of the electric field, holes from the n region to the p region, electrons from the p region to the n region, after turning the circuit form a current. This is the photovoltaic solar cell works.


solar power generator solar power in two ways, one is light - heat - electricity conversion mode, the other is light - electric direct conversion method.

(1) light - heat - electricity conversion mode through the use of thermal power generated by solar radiation, usually from the solar collectors to heat absorbed by the working fluid is converted into steam, and then drive steam turbine power generation. Before a process is light - thermal conversion process; after a process is heat - electricity conversion process.

(2) light - electric direct conversion approach is the use of the photoelectric effect, the direct conversion of solar radiation into electrical energy, light - the basic electrical conversion device is a solar cell. Since the solar cell is a photovoltaic effect and solar energy directly into electrical energy device, a semiconductor photodiode, when the sun light to the photodiode, the photodiode will be the sun's light energy into electrical energy generated current. When the number of batteries connected in series or parallel can become a relatively large output power of the PV array.

This article comes from http://www.storagebattery-factory.com/news/what-is-solar-energy-generation-system.html.

Difference LifePo4 Battery and Ternary Battery

Lithium battery electric car is one of the most common types of batteries, although its inception in 1970, the time is not long, but with a high energy density, long cycle life and other characteristics quickly occupied the vast majority of electric vehicle battery market part of country. Today, in the sale of electric vehicles with lithium batteries mainly have two kinds of LifePo4 batteries and ternary lithium. So ternary LifePo4 battery which different but it?

Battery power is the core of electric vehicles, pure electric vehicles are the only source of driving energy is directly related to the power performance, battery life of electric vehicles, but also directly related to the safety of electric vehicles. The cost of new energy vehicles constituted, the battery-powered systems accounted for 30-50% of the cost of new energy vehicles. And since the birth of electric vehicles, battery technology has restricted the practical process of electric vehicles. Increase power density, energy density, life and cost reduction has been the core of electric vehicle battery technology research and development.

Lithium battery electric car is one of the most common types of batteries, although its inception in 1970, the time is not long, but with a high energy density, long cycle life and other characteristics quickly occupied the vast majority of electric vehicle battery market part of country. Today, in the sale of electric vehicles with lithium batteries mainly have two kinds of LifePo4 and lithium three yuan. At the same time, it also can be used in solar powered portable generator.

What is the difference ternary LifePo4 batteries have it?

Outline Package

Lithium-ion batteries can be divided into a square battery, soft pack batteries and cylindrical batteries.

Material system

The current mainstream of LifePo4 battery, battery ternary materials, respectively, are defined by LifePo4 and ternary materials as cathode materials for lithium ion batteries. Ternary material refers Ni, Co, Mn or Ni, Co, Al three metal elements as the core element of the cathode material.

Overview

LifePo4 monomer, the energy density of 120Wh / kg, after the group was 80Wh / kg; ternary lithium monomer, the energy density of 180Wh / kg, after a set of energy density 110Wh / kg. From the data point of view, in terms of energy density, three better than the LifePo4 battery; in cycle life, the two equivalent single cell cycle life of greater than 3000 times the battery group, due to the use of working condition becomes severe and complicated, there will be some reduction in life expectancy, the battery life of six years, equivalent to 150,000 kilometers. EV200 battery used ternary lithium battery.

Currently the energy density of LifePo4 has basically reached the ultimate theory, the energy density of the battery as well as three yuan a lot of room for improvement. Comprehensive capacity density, power density, cycle life, low temperature performance, etc., the overall performance is better than ternary battery LifePo4 batteries.

This article comes from http://www.storagebattery-factory.com/news/what-is-diffrernt-lifepo4-between-ternary-battery.html.

What is Ternary Polymer Lithium Battery

Brief Introduction

Terpolymers lithium electrode material is corrected using lithium batteries - Mn lithium nickel cobalt cathode materials, lithium ion battery cathode material there are many, mainly lithium cobalt oxide, lithium manganese, nickel, lithium, ternary material , LifePo4 batteries. Currently ternary material batteries instead of lithium cobalt oxide core before the widespread use of laptop batteries widely used in the field of hair.
Parameter

Nominal Capacity: 1250mAh Standard discharge continuous current: 0.2C
Maximum continuous discharge current: 0.5C
Discharge: -20 ~ 60 ℃
Size: MAX 9.5 * 35 * 52mm
Finished resistance: ≤150mΩ
Lead Model: GB wire UL1007 / 24 #, line length 55mm
Protection parameters: overcharge protection voltage / per string 4.325 ± 0.025V
Over-discharge protection voltage 2.5 ± 0.05V
Overcurrent value: 2 ~ 4A

Performance

In terms of the capacity and safety of the material more balanced, normal cycle performance better than lithium cobalt oxide, preliminary technical reasons only its nominal voltage 3.5-3.6V, be limited in terms of scope, but so far, with the formula constantly improve and perfect structure, the nominal battery voltage has reached 3.7V, the capacity has reached or exceeded the level of lithium cobalt oxide.

Status

The world's five major brand batteries SANYO, PANASONIC, SONY, LG, SAMSUNG has introduced batteries, a considerable part of the notebook battery cable ternary materials have replaced the previous LEP batteries with cobalt ternary materials, batteries, SANYO, SAMSUNG batteries column is halted and turned ternary lithium batteries cobalt batteries manufactured at home and abroad of small high-rate battery power most of the ternary cathode material. 

This article comes from http://www.storagebattery-factory.com/news/what-is-ternary-polymer-lithium-battery.html.

Why Sotrage Battery Need BMS (Battery Management System)

Remote meter equipment due to its special working conditions and work requirements of the battery is very high. It requires the battery has a longer continuous power supply capacity, battery life time is often needed to reach a year or even longer.Because of the lithium batteries high voltage, small size, light weight, high energy density, no memory effect, no pollution, low self-discharge, long cycle life, the many advantages of being widely used in remote monitoring long standby instrument. Compared with nickel-metal hydride batteries, lifepo4 batteries 30%-40% lighter, energy 60% higher than it. However, lithium also has serious flaws, is summarized in the following two aspects:

Safety

Lithium battery security is poor, when an explosion and other defects. Especially lithium cobalt oxide cathode materials for lithium batteries can not be high-current discharge, poor security. In addition, almost all kinds of lithium battery overcharge or over-discharge can cause irreversible damage. Lithium battery temperature is extremely sensitive: if used in high temperature conditions, may cause decomposition of the electrolyte, combustion or explosion; temperature is too low will lead to a marked deterioration in the performance of lithium batteries, affect the normal use of the equipment. Due to limitations in the battery production process, the internal resistance of each cell, there will be differences in the capacity etc. When a plurality of battery cells in series, will cause the rate of charging and discharging batteries various inconsistencies, which led to the utilization of the battery capacity is low. In view of this, the lithium battery in the actual use of the process often requires special protection system to monitor the health status of the battery, lithium batteries use to manage the process. Shows the decomposition of the electrolyte of the lithium battery. These lithium batteries also can be used in solar powered portable generator.

Maintainability

Lithium battery capacity at low attenuation and power makes the device unable to accurately predict poor maintainability. A long line of instruments require periodic battery replacement, and remote monitoring equipment to work sites scattered on the road between the various remote sites, so the battery replacement huge workload and costly. In order to reduce the maintenance workload, reduce maintenance costs, it requires a battery management system with an accurate estimate of the state of charge function to accurately grasp the battery state of charge, battery replacement and more destinations; also need a battery management system with a lower its power consumption to reduce the frequency of maintenance and prolong battery life. Therefore, long-lasting power for remote monitoring instrument, the rational design of battery management system to maintain the device has a very important significance.
However, the working characteristics of remote monitoring instruments and inherent characteristics of lithium batteries make such an application developed to meet the requirements of the battery management system becomes very difficult. There are several factors: First, from the working characteristics of distance measuring instruments concerned, in order to reduce power consumption, remote measurement instruments typically carried out periodically sleep and wake, and its current work is dynamic, wake-up phase of the current much higher than hibernation, but the wake-up phase of the working time is far less than the dormant stage; secondly, lithium battery discharge curve is very flat, the main power concentrated in 3.6V voltage or more, and then, with further reduction in voltage, battery charge began a sharp decline, remote instrumentation can not be issued in accordance with the battery voltage is low battery alert; Finally, the solar power battery self-discharge rate changes with temperature fluctuated for work in the field of instrumentation, the temperature conditions are very extreme, and further increase the battery is difficult to predict. Existing battery management system is difficult to adapt to these functional and performance requirements, based on the background of the subject is proposed.

This article comes from http://www.storagebattery-factory.com/news/why-sotrage-battery-need-bms.html.

Monday, 10 October 2016

Solar Energy Storage Battery Technology Get a Revolutionary Breakthrough

When natural gas, coal, oil and other non-renewable resources, frequent emergency, energy is increasingly becoming a bottleneck for social development, the solar,wind and other renewable resources has become a new driving force for economic development. At the G20 summit, renewable energy issues, environmental issues will become the object of world leaders concerned, and as the organizer of China is more practical action to demonstrate its adherence to the concept of environmental protection, solar power energy storage technology also achieve a breakthrough, and further summit environmentally friendly match.

100Ah 48V solar battery storage
Solar energy battery storage in the near future will occupy an important position in the world energy consumption, not only to replace part of conventional energy sources, and will be the subject of the world's energy supply. By 2030, renewable energy in the total energy mix accounted for more than 30%, while the proportion of solar battery storage in the world's total electricity supply will also be more than 10%.
LD1250B LifePo4 Solar storage battery
China has become the world's leading producer of solar storage batteries. 2007 national solar energy battery storage production reached 1188MW, an increase of 293%. China has already overtaken Europe, Japan, the world's solar storage battery manufacturing superpower. In the Yangtze River Delta, the Bohai Sea, the Pearl River Delta, Midwest, it has formed a unique solar energy storage battery industry cluster, a growing number of national companies to enter the field of solar energy.
LD4840B Household energy storage battery
In addition to solar energy storage batteries, lithium batteries, secondary batteries, sodium-ion batteries have international forefront of technological breakthroughs. In April 2015, new progress in the lifepo4 battery pack BMS design, solution-oriented high security lithium-ion batteries, battery management systems difficult and hot issues long-life operation, the use of the proposed method for NASA Ames Strawbery prediction Center three more data to fit a standard battery. 

Lithium-ion Battery VS LifePo4 Solar Energy Battery Storage

LifePo4 solar energy battery storage, refers to as a cathode material for LifePo4 batteries. Lithium-ion battery cathode material of lithium cobalt oxide, lithium manganese, nickel, lithium, ternary materials, lifePo4. Wherein the lithium cobalt oxide cathode material is currently used in the vast majority of lithium ion batteries.

LifePo4 Solar Energy Battery Storage Eight Advantages

Improve safety performance

lifePo4 crystals of P-O bond firm, difficult to decompose, even at high temperature or overcharge will not be as lithium cobalt oxide as the structure collapses fever or strong oxidizing substances, it has a good safety profile. There are reports that practice acupuncture or short experiment, we found a small part of the sample combustion phenomenon occurs, but there was one case of bombing, and overcharge used in the experiment far beyond the self-discharge voltage of high voltage charging several times and found that there are still explosions. Nevertheless, the overcharge security than ordinary liquid electrolyte lithium cobalt oxide batteries, has been greatly improved.

Improve life

LifePo4 refers to the use of lifePo4 as the cathode material for solar power storage solutions.
LP-4840P-Solar energy storage battery solutions-2
Long-life lead-acid battery cycle life of about 300, the maximum is 500, while the lifePo4 solar storage battery , the cycle life of more than 2000 times the standard charge (5 hour rate) used up to 2000 times. With the quality of lead-acid batteries is the "new six months, six months old, Maintenance and six months", most will be from 1 to 1.5 years, while the lifePo4 used under the same conditions, the theoretical life expectancy will reach 7 to 8 years. Taken together, the cost performance is theoretically more than four times the lead-acid batteries. High-current discharge high current 2C fast charge and discharge, under the dedicated charger, 1.5C charge you can make in 40 minutes the battery is full, the starting current of up to 2C, but no such performance lead-acid batteries.

Good high temperature performance

lifePo4 peak heating up to 350 ℃ -500 ℃ and lithium manganese oxide and lithium cobalt only about 200 ℃. Wide operating temperature range (-20C - + 75C), there is high temperature characteristics of lifePo4 peak heating up to 350 ℃ -500 ℃ and lithium manganese oxide and lithium cobalt only about 200 ℃.

High capacity

The ordinary batteries (lead-acid) greater capacity. 5AH-1000AH (monomer)

No memory effect

Rechargeable solar energy storage batteries in full condition after letting go often in work, the capacity will be lower than the nominal capacity value rapidly, a phenomenon called memory effect. Such as nickel metal hydride and nickel cadmium batteries exist memory, lifePo4 is no memory effect, no matter what state the battery can recharge it with no need to recharge is done.
LP-4850P-Solar energy storage battery solutions-3
Light weight

The volume of the same specifications capacity lifePo4 battery pack is the volume of lead-acid batteries 2/3, 1/3 weight of lead-acid batteries.

Environmental protection

The solar energy storage batteries are generally considered to be free of any heavy metals and rare metals (nickel-metal hydride batteries to be rare), non-toxic (SGS certification through), non-polluting, in line with European RoHS regulations as an absolute battery green card. So the reason to be optimistic about the lithium battery industry, mainly environmental considerations, so the battery and included in the "863" national high-tech development plan "fifth" period, becoming the state's key projects to support and encourage development. Chinese exports of electric bicycles will increase rapidly, and enter the European electric bikes have been with the requirements of non-polluting batteries.

But some experts said the environmental pollution caused by lead-acid batteries, mainly in the business of non-standard production processes and recycling sectors. Similarly, lithium batteries are the new energy industry is good, but it can not avoid the problem of heavy metal pollution. Metal materials processing lead, arsenic, cadmium, mercury, chromium, etc. are likely to be released into the dust and water. The battery itself is a chemical substance, it is possible to produce two kinds of pollution: the production engineering process fecal contamination; the second is scrapped after battery pollution.

lifePo4 has its drawbacks: such as poor low temperature performance, small cathode material tap density and volume capacity of lifePo4 is greater than the lithium cobalt oxide lithium-ion solar battery storage, and therefore does not have the advantage in miniature solar battery storage. And when used in motive power batteries, lifePo4 batteries and other batteries, battery consistency need to face the problem.

Comparison of battery

The most promising are used in power lithium-ion solar battery storage cathode materials are modified lithium manganese oxide (LiMn2O4), lifePo4 (LiFePO4) and nickel cobalt manganese lithium (Li (Ni, Co, Mn) O2) three yuan material. Nickel, cobalt and manganese lithium cobalt ternary material due to a lack of resources and nickel, and cobalt into high price volatility and other factors, generally considered difficult to become electric vehicle power lithium-ion battery of the mainstream, but with manganese spinel lithium mixed within a certain range. 

This article comes from http://www.storagebattery-factory.com/news/lithium-ion-battery-vs-lifePo4-solar-energy-battery-storage.html.

Dehydration Problem Lithium Battery Cathode Material LifePo4

Dehydration is a lifepo4 battery pack materials eternal topic, both positive and negative material production, or electrode production process have to face the problem of dehydration. FePO4 precursor material is both LiFePO4 material, but also can be used alone as the positive electrode material, so the problem of dehydration FePO4 material that we can not avoid the problem.

Generally iron phosphate dehydration process is divided into two parts: the first one, mainly to take off some of the material in the free water which is very easy to remove, the temperature is lower.

100Ah 48V solar battery storage
Second, the crystallization of the material off the water, the water molecules with the iron phosphate materials chemically combined manner, it requires a higher activation energy - that is, higher temperatures, complete removal of the water to this part, but the study reaction kinetics of the process is not a lot.

Preparation of iron phosphate commonly used ferric sulfate or other soluble ferric iron source, phosphoric acid or phosphate as the phosphorus source, NaOH as PH regulator, by co-precipitation methods.

Actual production is generally controlled between 1.6-2.0 PH, PH is too high when it may precipitate Fe (OH) 3 impurities, and PH value is too low will cause the precipitation of Fe3 + incomplete. The precipitate is filtered and washed after high temperature sintering is required, this process is mainly for two purposes, first off FePO4˙2H20 material in the water, and secondly to make FePO4 crystal material fully developed, in order to ensure a complete crystalline material type. These lifepo4 battery usually can be used in solar powered portable generator.

TG was found in the range of 50-223 ℃, FePO4˙2H20 material appeared in 20.23% of weight loss, which is mainly FePO4˙2H20 material two crystal water is removed, and then as the temperature rises, FePO4 material does not continue to appear weightless, so the dehydration process is mainly done in this process.

In 736 ℃ appeared an exothermic peak, and there was no loss of quality, which indicates that at this temperature, the material FePO4 crystalline transition occurs subsequent XRD diffraction analysis also found that, at 700 ℃ under synthetic material FePO4 diffraction peak is wide, part of the characteristic peak does not appear, at this temperature synthetic crystalline material FePO4 incomplete development of poor crystallinity.

The temperature was raised to 800 ℃, all characteristic peaks were appeared, but the characteristic peak intensity is still low, wide, indicating at the same temperature, crystal growth is still not complete, when the firing temperature is raised to 900 ℃, can pay attention to this time appears not only all the peaks, a characteristic peak of hexagonal (206) / (302) has also been completely separated, indicating FePO4 crystalline material well-developed.

LP-4850P-Solar energy storage battery solutions-3
At 900 ℃, FePO4 prepared material belonging to the hexagonal lattice parameters a = 0.50330nm, b = 0.50330nm, c = 1.12470nm, having α- quartz structure which is conducive to the lifepo4 batteries material embedded into FePO4 .

Kinetic studies on the dehydration FePO4 not much, FePO4 material dehydration mechanism and kinetics study has important implications for the development of the production process iron phosphate material.

The use of TG-DTG-DTA thermal analysis to study the mechanism and kinetics of dehydration FePO4˙4H20 materials, the study found FePO4˙4H20 material at 200 ℃, there were two DTG DTA exothermic peak and peak rate of weight loss, dehydration process is a two-step reaction, calculations show that the reaction is a D4-Fn-step reaction in which the activation energy of the reaction is D4 79.62KJ / mol, activation energy of the reaction Fn 103.04KJ / mol.

The study found no effect on the heating rate in the dehydration reaction mass, so long as the heating temperature reaches the appropriate temperature can be sufficiently removed FePO4 water. This has important implications for the sintering process of iron phosphate.

This article comes from http://www.storagebattery-factory.com/news/dehydration-problem-cathode-caterial-fePo4.html.