digital batteries

2.2 The path that leads to ear discharge capacity of the battery

In the discharge conditions at high speed, the structure of different cells, the design methods are also very different ear. Winding structure of lithium-ion batteries can be very smart multi-electrode welding pole number, so that the initial discharge rate is high, the battery is more than one region within the low internal resistance, more current density, the reaction rate, which mitigation if the response of unipolar ears. The layered structure of lithium-ion can reverse the pole piece electrode design of a pole, laminated ear when the opposite of the battery leads, one on each side of each ear and one ear negative cathode, anode between ears electrical connections, electrical connections between the ears negative pole to reach the discharge current, for current distribution. LP140WX1 (TL)(02) LP140WX1 (TL)(03)

The winding structure of a fixed size battery model lithium-ion batteries, an ear multipolar will reduce the nominal capacity of the battery, and the growing number of ears, then increase the difficulty of aluminum plastic sealing film, the aluminum between the film and very sensitive to the ear Pre-sealing of negative phenomena, which cause the battery to short circuit, gas, and leaks from hidden dangers. The layered structure of lithium-ion batteries, most ears only son of a pair of back again, there is also an aluminum foil sealing difficult problem. Ear in the design of the battery, usually a negative value is very ear design, but a large aspect ratio for the type of battery, if the use of the ear ipsilateral to the road very, very ears, width of the size is very limited to the maximum discharge of the battery can not meet the requirements of very ear led to this moment, can use reverse ear positive and negative leads.

By changing the way positive and negative leads to a very ear 20C discharge capacity of the battery. The ND-1 and ND-4 cell 20C constant rate of 2.75 V, 20C receive the battery discharge curve quickly Figure 3. LP140WX1 (TL)(05) LP141WX1 (TL)(01)

This can be seen in Figure 3, the positive and negative son of a very negative way regardless of the ear, or through conduit ipsilateral, the rate of discharge of the battery of the platform and the flow has little influence.

Nickel plated copper 2.3 Capacity negative ear discharge of the battery

Currently, most researchers on the electrode design, the choice of anode and cathode materials, anode and electrolyte formula is optimized to improve performance in firing rate of battery. Chengjian Cong, which evaluate the performance of the various factors that influence optimized battery combination, made with a nominal capacity of 1100mAh battery, the rate of battery discharge at 20 ° C, the maximum surface temperature of cells is 75 ℃, and 23 C discharge rate, surface temperature maximum battery life of 83 ℃. This shows that the use of these improvements could increase the discharge capacity of the battery, but can not solve the serious problems of heat from the battery to increase the cooling rate of the battery, also need design a study of the battery. LP141WX1 (TL)(02) LP141WX1 (TL)(A1)

Through this experience, the ND-1 Lithium-ion designed for the ear better. Is the study, the discharge capacity of the battery and the speed of temperature change when the surface of the cell to conduct a comprehensive study, the results presented in Figure 4 and Figure 5.

You can see in Figure 4, the battery in the 20C, 25C and 30C discharge rate, the maximum surface temperature of the cells were 61 ℃, 67 ℃ and 75 ℃. The outer surface of the battery temperature is inside the battery caused by heat conditions, the negative pole of the ear, nickel-plated copper can improve the rate of heat from the battery to reduce the serious phenomenon of heat from the cell surface.

Can be seen in Figure 5, with increased throughput, reduced platform discharge of the battery, but a minor reduction in flow capacity and flow rate at 30 ° C when the battery is no phenomenon of flatulence, indicating that the battery has excellent discharge capacity. Analysis of high rate discharge, the use of ear copper-nickel cathode, can actually improve the rate of heat dissipation from the battery to improve the discharge capacity of the battery. In addition, with the increase in firing rate, the rate of lithium ion conduction in the electrolyte and the diffusion rate in the film very will increase, thus the high performance battery discharge will increase. hp pavilion dv6000 battery hp pavilion dv8000 battery

Figure 6 is the ND-1 cell 20C and 25C of the life cycle flow plan, the charge and discharge system, such as 1C constant current charge to 4.2V, the voltage constant current is less than or equal 0.05C and at a constant rate discharge current 20C and 25C at 2.75V.

Can be seen in Figure 6, with increasing flow rate, decrease the battery capacity increased. ND-1 Battery and 20C rate of 300 weeks, the capacity retention rate was 80%, the discharge rate 25C 200 weeks, the capacity retention rate was 78%. The battery has a good cycling performance of high rate, high rate of discharge to meet the needs of the environment. hp pavilion dv4000 battery hp pavilion dv5000 battery

3 Conclusion

In this paper, a series of experiments, the results show that changing the battery inside the ear design can be very effective in improving high-yield lithium-ion battery discharge. Pole Cathode copper-nickel discharge process at high speed, can reduce the polarization of the battery, the discharge rate of the battery to improve performance and reduce the surface temperature of the battery, thus further improving the rate cycle life of the battery.

Through experiments, copper plated, with big ear 15mm negative 2Ah batteries, the battery has a good rate of discharge efficiency, and reliability. The battery can be reached 30C discharge rate, discharge curve smoothly, and the surface temperature of the battery has not significantly increased after 300 cycles after the ability to 20C discharge rate can maintain the original capacity of 80 % after 200 cycles after discharge capacity rate of 25C may maintain the original capacity of 78% which indicates good performance of the rate of battery discharge. hp pavilion dv1000 battery hp pavilion dv2000 battery

In recent years, with model aircraft, electric toys, electric tools and the rapid development of lithium-ion battery discharge rate performance requirements are becoming higher, but the commercialization of lithium-ion more difficult 20C achieve continuous flow, primarily because its rate of battery discharge when a high fever listen very serious battery temperature is too high overall, making it easier to battery thermal runaway, leading to discharge capacity of the battery and the bike’s performance deteriorated. To get a good rate capability and reliability of lithium-ion batteries, high current discharge, first to minimize the battery produce large quantities of heat, partly to improve the cooling of battery level, the first method can improve the materials positive and negative electrolytes, positive and negative pole piece design to start, which can be optimized to increase the cellular structure of the battery cooling rate, which improves safety of the battery. LP133WX1 (TL)(B3) LP133WX3 (TL)(A1)

energy transfer very ear with the outside world is the battery holder, so a rate of battery discharge, the higher the conductivity of the very ear can improve the rate of battery discharge early discharge performance. Conventional lithium-ion batteries using nickel from ear ear very, low conductivity, conductivity 140000S/cm, positive aluminum ear, the electrical conductivity of 369 000 S / cm. The dump at high speed because of the negative conductivity of the lower ear, causing the surface temperature of the battery is too high, which affects performance at high discharge rate battery. The nickel-plated copper anode has a good ear conductivity, its conductivity near the conductivity of copper, approximately 584,000 S / cm. This article in the current high rate system based on the cathode copper-nickel very ears as a research material over the ear, ear size and extremely leads way on the capacity lithium-ion battery discharge and the rate performance bike. LP133WH1 (TL)(A1) LP133WH2 (TL)(A3)

Experience

1.1 Preparation and design of the battery

The positive active material LiCoO2, superconductive carbon black and graphite driver KS6 SP mixed with a binder PVDF in the preparation of slurry cathode. The negative active material of carbon black MS MCMB and superconducting mixed with PVDF as a binder in the preparation of slurry cathode. Will be positive, negative suspension of a coating and roll, the film is thin and porous and the positive film negative.

By traditional methods of making lithium-ion batteries will be positive, negative pole piece laminate structure was prepared by the nominal capacity of 506,680 2Ah lithium-ion batteries.

1.2 The main test instrument

With lithium-ion SB-9088K-3A automatic detection device (production Guangzhou) and points in the capacity of the battery, rechargeable battery with BK-7024L/60 Test Facility (Guangzhou production) rate of return the battery discharge test, heat treatment galvanic detection flow surface temperature of the battery. LP140WH2 (TL)(A1) LP140WX1 (TL)(01)

2 Results and discussion

2.1 Anode material and size of the discharge capacity of the ear drum

In the discharge conditions at high speed, the choice of size model of the ears of the decision not only drums but also depends on the maximum discharge current of the battery. This ear by changing the cathode material and size, ear negative 20C rate discharge performance of the battery and the surface temperature of the battery. The ND-1 ND-2 and ND-3 batteries to 20C constant rate of 2.75 V, the discharge curve of battery 1, the rate of the discharge curve of the battery temperature Surface Figure 2.

You can see in Figure 1, the initial discharge voltage of the battery compared to: ND-1> 2-ND> ND-3 ND-1 cell platform high voltage discharge, the discharge curve smoothly and discharge voltage initially higher, while the ND-2 ND-3 batteries and cells appeared at 3.15V and 3.12V voltage surges, spikes appear due to the high rate discharge, the battery in the Within the region of the electrode reaction is very uneven. Early in the year, listening very low in the vicinity of the resistance, the current density is high, the electrochemical polarization is high, it voltage curve peaks later in the discharge capacity of the region near the exhaustion of most of the ears, and away from the pole region of the ear, part of the temperature increase is relatively slow, which is the phenomenon of the rise in tension. hp pavilion zv5000 battery hp pavilion zv6000 battery

ND-1 with the battery and the comparison of ND-3 discharge rate curve can be seen, 10mm wide, ear discharge very 40A, most ears in the vicinity of the electrochemical polarization affecting performance the rate of battery discharge, which indicates that the ear with a very large size will improve the discharge capacity of the battery. By comparing Figure 1 and ND-1 ND-2 discharge rate curve shows a very different material from the ear the same size same performance discharge rate of the battery will have a big impact, ear negative materials Copper nickel battery better discharge capacity.

By studying the surface temperature curves of the battery discharge capacity can be seen in Figure 2, ND-surface temperature to a lower cell battery ND-2 is about 10 ℃, it because NA-2 cells with poor electrical conductivity of the nickel cathode ear, flow during the Great, near the highest temperature region of the ear is negative then this part of the regional production of large quantities of Joule heat and the temperature has risen too quickly, and a good electrical conductivity of copper cathode nickel ear material, can effectively reduce the ear region very electrochemical polarization, the slower rise in temperature surface of the battery, thereby improving battery safety. These results indicate 2Ah battery anode rates with 15mm nickel-plated brass ear discharge is not only a good performance, but also has better security and reliability. hp pavilion dv9000 battery hp pavilion zd7000 battery

5, the discharge of low voltage to 0V with a load

Some good performance LiFePO4 battery voltage discharge to 2.0V after the cessation of the continuous release of discharge to the battery voltage is 0V, little effect on cell performance. The test is: the battery at 0.5C to 1C, after a complete discharge to 0V, the positive and negative, plus a 1W resistor connected, the batteries were put into two groups 7 days and 30 days; because later filled by 0.5C 1C discharge, the two sets of test results of battery are: hp 520 battery hp 530 battery

1) Place a 7-day, no leakage, good performance, the discharge capacity of 100%;

2) Place a 30 day, no leakage, the discharge capacity is 98% after 3 charge cycles back to 100%.

6, no pollution to the environment

LiFeO4 battery of non-toxic environment, toxicity was significantly lower than LiCoO2, LiNiO2, LiMn2O4 as cathode material for lithium-ion batteries.

7, low price

Since the characteristics of LiFePO4 above, it is very strong impulse, will be gradually replaced in many areas of cobalt, lithium oxide cathode material of lithium-ion batteries. hp 550 battery hp Mini 110c battery

LiFePO4 battery charger

LiFePO4 batteries are the main parameters of the nominal voltage is 3.2V, the termination of the charging voltage is 3.6 ± 0.05V, discharge voltage is 2.0V end. Because of his denunciation of the charge voltage and end voltage lithium-ion battery (4.2V) different, so they need LiFePO4 battery charger.

If Yun Electronics Co., Ltd. Shanghai in 2007 to develop the battery charger IC CN3058 and CN3059 LiFePO4. Performance of the two charger IC is basically the same, the difference is that the maximum load current former ICH = 500 mA, while the second is the PCI = 1000 mA, the first is 8-pin SOP-8 package (Lead) , which was 10 pins 3mmx3mm The DFN (unleaded). This article describes the composition of the CN3058 charger. hp pavilion dm1 battery hp pavilion dm3 battery

CN3058 features of the composition of the charger

CN3058 is a unique piece of LiFePO4 batteries for constant current, voltage linear charger IC constant. The composition of the CI loader with the main features: RISET resistance device with a charging current can be set to the maximum load current up to 500mA input voltage 4 ~ 6V, can use the USB port or 4.5 ~ 6V AC / DC power, the charger circuit is simple, the less external components and low cost, the discharge cells on-off (<2.0V) with the current pre-load low; internal circuitry of power management, if the junction temperature of the chip exceeds 115 ℃, automatically reduces the charging current for thermal protection, allowing users to charge current can be higher to improve the charging efficiency; has two LEDs to indicate charging status and practiced the end of the leaflet have input voltage less than 3.61V, the output latch function, battery temperature monitoring function, it also has a unique feature: RVSET peripheral resistance, may increase the voltage constant. This feature can be used to terminate the charge voltage of 4.2V rechargeable lithium-ion battery and charger may consist of battery acid and three single 4V battery charger Ni-MH. Sony VGP-BPS14/S battery Sony VGP-BPS14B battery

Formed by the shipper to load 0.35Ah CN3059 LiFePO4 ~ LiFePO4 Battery 2Ah. The application: a miner’s lamp, LED emergency lights, warning signs, model cars, model boat, airplane model toys and electrical in the unit, with rechargeable LiFePO4 battery (model RCR123A) Replacement Lithium disposable (CR123A type, size and RCR123A the same type) communication devices, portable medical and test instruments in the field and small power tools.

2. The rechargeable lithium-ion or LiFePO4 battery charger circuit

A kind of lithium-ion battery and LiFePO4 battery charger circuit of Figure 5. Figure 4 The difference is in the circuit, the addition of a SPDT switch S and RVSET resistance, hit the top of the switch is 3.6V rechargeable lithium-ion battery (the end of the charging voltage is 4.2 V); switch hit in the bottom is full LiFePO4 battery. Sony VGP-BPS14 battery Sony VGP-BPS14/B battery

In the lithium-ion battery, its voltage Vbat final charge to 4.2V, Vbat is RVSET and relationship:

Vbat (V) = 3.6V 3.04 × 10-6 (A RVSET) × (Ω)

For 4.2V generation – in style, RVSET = 197.37kΩ. Obtained by the standard resistance 196 kΩ. RVSET should be 1/8W ± 1% precision resistors.

Before charging the battery under load switch location is correct.

3. Charge 3.2V rechargeable battery (model RCR123A) charger circuit

Many camera model used two 3V CR123A lithium batteries for power once. Are now possible with LiFePO4 battery (model RCR123A) to replace, high capacity, the economy is good. Circuit of Figure 6 (left) below. Figure 6 (right) is the poster gallery CR123A charger and external dimension (RCR123A is LiFePO4 battery, the same size CR123A).

RCR123A a capacity of 500 ~ 750 mAh, 500mA load with greater efficiency.

4.5V/1200mA Charger Adapter AC / DC (power plug-type) power. Double LED light emitting diode (anode), simplifies the structure. Sony VGP-BPS13B/S battery Sony VGP-BPS13S battery