Digital battery

Improving the packing density material can significantly improve the volume ratio of the battery energy, while the size of tap density and packing density has a close relationship, so as to improve the tap density material can increase size of the energy of the specific battery. Table 1 shows, using three sections of samples prepared by the tap density maximum can reach 2.1 g cm-3 · The response to high temperature samples directly to the minimum density of tap sample SEM shown in Figure 3, Map 3 can be seen, the product of spherical particles, particle size, mostly between 8-10 microns particles together in the small grains, 1 # 2 # samples samples and comparing the accumulation of dense grains, and # 3 samples conglomerate more grain, which leads to the tap density less reason. LP101WS1 (TL)(B2) LP101WS1 (TL)(B3)

 

2.2 The electrochemical properties of the sample

Figure 3 is the ability of the sample, the curves of the room temperature cycle, voltage range of charge-discharge 3,0-5.0 V, the first charge and discharge current density of 0.50mA · cm-2 , respectively, charge and discharge current density of 1.00 and 2.00mA · cm-# 2,1, 2 and 3 # # samples, initial discharge capacity were 123.4,129.4 and 121.3mAh · g-1. After 50 cycles, the retention capacity of their own, as shown in Table 1. can be seen in Figure 2, the discharge current density of 2.00mA · cm-2, the initial discharge capacity of the lower part, with the number of cycles increases, capacity has increased, after reaching the maximum and then slowly decay. Sample 1 after 50 cycles in the year not yet reached maximum capacity. LP121WX3 (TL)(A1) LP133WX1 (TL)(A1)

 

Cycle early in the process of Li + deintercalation from eight tetrahedral positions held, but not all Li + are outside the cathode material in lithium metal anode embedded in the passage to a small part of the lithium ion deintercalation is not to stay up cathode material, with the cycle progresses, the material of lithium ions occupy the post 8 activation occurs, the original can not be a prolapse of Li + deintercalation make the material are also occurred in the carrying capacity has steadily increased. In the discharge process, the deposition of lithium in the lithium anode surface continues dissolved and moved to the cathode in the process of lithium losses exist (at the beginning of SEI film was formed), carrying capacity and discharge capacity equivalent to both charge and discharge efficiency above 99%, while its discharge capacity is also done with the cycle constantly increasing after a period of movement, to participate in migration between the positive and negative Li + in the cathode material has been fully integrated into broader, integrated discharge capacity up in a cycle later, the attenuation of the material normal discharge capacity occurs. LP133WX1 (TL)(A2) LP133WX1 (TL)(C1)

 

Figure 4 is a sample at the output of different current density of the discharge curve (material already 2.00mA · cm-2 current density of 50 cycles). As shown in Figure 4, using the method in three steps of the material increases with xCuxO4 LiMn1.5Ni0.5-current density discharge, the discharge capacity decreased slightly in the high current (4.00 mA · cm-2) under discharge performance, the discharge capacity of the current density of 0.30mA · cm-2 of 97.5% when the platform with the discharge voltage increasingly current density decreased slightly, probably due to the discharge current density, the polarization of the electrodes increased the load speed is often greater than the speed of the electrode reaction, the reaction in the polarization of the electrode polarization the dominant role in the measurement of the electrode reaction irreversible increase in voltage as the current increases. LP133WX1 (TL)(B1) LP133WX1 (TL)(B2)

 

2.3 Graphite as negative electrode material of the electrochemical properties when

Figure 5 is a sample of graphite as the anode of the first charge and discharge curves of the time. In a graphite anode, the current density of 0.50mA · cm-2, the first discharge capacity of 107mAh g-1 material ·, effective the first charge-discharge was 85.1%, or about 4 5 platform voltage. In the first method of load from the cathode material of some lithium-ion deintercalation supplied to the anode SEI layer formed on graphite surface, the remains of the lithium ion is inserted between the actual participation of extrusion of lithium necessary positive and negative - and the first cell, low efficiency, while the graphite anode of the effectiveness of the first charge-discharge (approximately 88%) lower, is also a load of battery discharge and efficiency reasons for initially weak current density of 2.00mA · cm-2 , LiMn1. 5Ni0.5-xCuxO4 initial discharge capacity 95.7mAh · g-1, the charge-discharge efficiency was 98.8%, or about 4.4 V voltage platform. After the first five charge-discharge (0.50mA · cm-2) cycle, the surface of the graphite anode to form a more stable SEI film, lithium-ion battery - stable prolapse, there is no loss Lithium-ion other, so that the charge and discharge efficiency. Compaq Evo N600c battery Compaq Evo N610c battery

 

Figure 6 is LiMn1.5Ni0.5-xCuxO4 respectively, lithium and graphite as the negative cycle when the yield curve (current density: 2.00mA · cm-2, approximately 1.3C). With lithium as the anode good cycling performance when, after the capacity after 200 cycles does not rot, the graphite anode, the 50 cycles, the retention rate after the retention capacity of more than 90% after 200 cycles was 67%, the average decrease Each was 1.7 ‰. In a metal lithium as the anode, lithium ions into the accident’s negative deposition - the process of dissolution in addition to training film lithium UTE necessary, the non-existence of losses in lithium-ion others, early exit has become a stable SEI film So, the next cycle, the capacity unchanged and in graphite as the anode, lithium-ion battery is inserted in place of negative - interpolation process off, charge and discharge process, the electrolyte and anode and the cathode is more between complex chemical reaction caused by its ability to rapid fading, the specific reasons for further study. LiMn1.5Ni0.5O4 undoped copper material after discharge 30 charge cycles, its discharge capacity is only 30% of discharge capacity on the initial capacity fading fast, and doped materials LiMn1.5Ni0.5 After xCuxO4 copper-holding capacity after 30 cycles was 93.4%, the retention capacity than the undoped material copper increased by 2 times. Therefore, the copper doped material for the carbon negative when performance is greatly improved. hp Pavilion dv7 battery hp 550 battery

 

3 Conclusion

Synthesized using different materials LiMn1.5Ni0.5 xCuxO4-cubic spinel structure and a single phase. With lithium for the cathode in the cycle when the performance is better, by three steps, produced by the bike’s performance of the best and largest of its tap density can be reached 2.1 g · cm-3. Materials under high current (current density of 4.00mA · cm-2) performance of the discharge, the discharge capacity is the current density of 0.30mA · cm-2 discharge capacity of 97.5%, showed a better discharge capacity; Materials LiMn1.5Ni0.5-xCuxO4 in graphite as the anode, the average capacity after 200 cycles per decay rate of 1.7 ‰, the retention capacity than non-doped LiMn1.5Ni0.5O4 copper material has increased by nearly 2 once the voltage is approximately 4.4V platform, is a promising cathode material for lithium-ion batteries. hp pavilion dv4 battery hp pavilion dv5 battery

Currently used in the cathode material lithium ion battery as LiCoO2, LiMn2O4 and new ternary materials of nickel, cobalt and manganese in voltage of about 4V, require high voltage must be more cathode material battery conjunction with the use, maintenance and use of this will bring many disadvantages. IBM ThinkPad T42 battery IBM ThinkPad T60 battery

 

If you can increase the voltage cathode materials, to improve the output voltage of the battery, then reduce the number of cells in series, and can greatly increase the power density of the battery. Study revealed that cations such as Cr, Co, Ni, Cu, Fe to replace some of LiMn2O4 spinel structure formed by manganese ions LiMxMn1.5-xO4, except in a voltage-4V flat regional platform, 5V will appear in the vicinity of a large voltage plateau. The platform LiM0.5Mn1.5O4 4V is removed, the platform voltage 5V. Study revealed that in these materials, LiNi0.5Mn1.5O4 relatively good electrochemical performance, but the cycle performance of pure LiMn1.5Ni0.5O4 poor performance and the rate can not meet the requirements, the needs of further improve the performance of large current discharge. In China, cathode materials in high voltage LiMn1.5Ni0.5O4 carbon negative when electrochemical properties of some reports, Japan has reported LiNi0.5Mn1.5 xTixO4 carbon-negative when the electrochemical performance. This document LiMn1.5Ni0.5O4 from this material by doping Cu, improved cycling performance, but also improved its performance in a current discharge, the negative electrode materials in carbon-cycle time performance was relatively good . IBM ThinkPad R51 battery LQ164M1LA4A

 

1 experience

 

1.1 Preparation of materials LiMn1.5Ni0.5-xCuxO4

For manganese sulfate, copper chloride, nickel sulphate and mixed in different proportions depending dissolved in deionized water, were used in the total concentration of 2.0 mol L-1 of the combined solution, the NaOH (4.0 mol L-1) and NH3 H2O · Preparation of mixed solution as precipitating agent, manganese sulphate, a solution of nickel sulphate and copper chloride mixture used in conjunction with the precipitating agent to be filled with a constant flow pump 1000mL deionized water reactor in the reaction control system of the reaction in the strict temperature, pH, stirring speed and stall, the reaction after the formation of precipitation washing, filtration, drying at 120 ℃ for 12h by Mn0.75Ni0.25 copper hydroxide composite nickel-manganese-yCuy (OH) 2. LP101WS1 LP101WS1 (TL)(A1)

 

Prepared by nickel-manganese over copper hydroxides and LiOH H2O · also by mixing atmospheric air after the reaction at high temperature, the product cooled to room temperature with the oven after sieving mill. Prepared by the sample into three steps 1, obtained by hydroxide Composite over nickel-manganese-copper mixed with LiOH H2O · reaction at 500 ℃ for 2h, cooling and then grinding after reaction at 500 ℃ for 2h The last 880 ℃ under 7am after oven at high reaction temperature cooling, grinding sieving, the sample was obtained 1, 2 # prepared two samples of the manganese-nickel hydroxide composite copper mixed reaction with LiOH H2O · 500 ℃ 2h and 7h reaction in 880 ℃ high temperature with the oven, after cooling, ground sieved to obtain samples of # 2, prepared by direct reaction of 3 # example, hydroxides copper-nickel-manganese and LiOH H2O · mixture directly into the reaction at high temperature 880 ℃ 7am after furnace cooling, grinding sieving get sample # 3. LP101WS1 (TL)(A4) LP101WS1 (TL)(B1)

 

1.2 Materials LiMn1.5Ni0.5 Benchmarks xCuxO4-electrochemical

The material prepared by high-LiMn1.5Ni0.5 xCuxO4 and conductive carbon black (4%) and PVDF (polyvinylidene fluoride) (6%) of the mixture, wrapped in aluminum foil as an anode of the battery ; film lithium or graphite as the anode membrane made of PP (polypropylene) / polyethylene (PE) / PP layer composite electrolyte is 1.0 mol L-1 LiPF6 (lithiumfluorophosphate) / EC (carbonate of ethylene) EMC + (Ethyl carbonate) + DMC (dimethyl carbonate) (1:1:1). Glovebox filled with argon gas in the assembly of electric batteries simulated detector CT-2001A blue at room temperature for charge-discharge test, the density of the first discharge current of 0.50mA · cm-2 (graphite as electrode 17 hours negative charge density and discharge current of 0.50mA · cm-2), the density of the discharge current round of 2.00mA · cm-2, voltage range 3,0-5.0 V.

 

1.3 The morphology and structure of materials

In scanning electron microscopy (JEOL JSM-5600LV) observed the morphology of the product, product structure using X-ray diffraction (MultiFlex) for testing. Compaq presario M2000 battery Compaq presario R3000 battery

 

1.4 Press the test product density

The sample in 20 ml graduated cylinder, record the quality of the sample, no change in the vibrations of the sample size to record the volume of the sample, the sample can be calculated tap density .

 

2 Results and discussion

 

2.1 The morphology and structure of the product

In the three samples prepared under different conditions of the X-ray diffraction spectra LiMn1.5Ni0.5-xCuxO4 shown in Figure 1. According to Kim et al [7] study, LiMn1.5Ni0.5O4 a cubic spinel structure (F3DM) Li occupy position 8, Ni and Mn occupy the position 16D, the oxygen in the position of 32nd, Cu Ni replace part of the entry octahedral 16d position. As can be seen in Figure 1, the prepared samples have a cubic spinel structure, a single phase composition, contains no impurity phase. In sample 1 and 2 XRD spectra of the sample (220) diffraction peak completely disappeared spectra LiMn2O4 the diffraction peak (220) indicates the presence of the skeleton in some spinel cations, that is, Li + and Mn 3 + crystal scramble on the grid, Li + appears instead 16D, while Mn 3 + is present in position 8, (220) peak completely disappeared, indicating these two samples, Li + and a small amount of the distribution of Mn3 + orderly arranged, they were in a tetrahedral 8a and octahedral position location 16d. Compaq presario 2100 battery Compaq presario 2500 battery

 

Calculated by the software Powderx 1 # 2 # # 3 samples and parameters of the cell, shown in Table 1. 3 #, 2 # 1 # sample cell parameters were lower, using three sections of the document prepared by a # minimum cell parameters, the best performance of the bike (on the early discharge capacity with the cycle without continually increase in computing capacity retention rate is based on the discharge capacity of the fifth as reference), the capacity after 50 cycles is unchanged, and in the process of loading and unloading cycle of state volume change during charge-discharge support reduces the spinel structure stability, structure to ensure a stable performance improvement cycle [9], lattice parameters shrink, increasing the strength of Mn-O bond, also allows the tunnel structure in three dimensions of the spinel material is stronger, so its best cycling performances, and directly derived from the reaction at high temperature lattice parameters of sample 3 the most significant change in volume during charge and discharge large spinel structure damage, poor performance of the bike, three samples of the performance curve of the bicycle shown in Figure 2. Presario V2000 battery Compaq presario 1700 battery

MnO2 catalysts as catalysts for oxygen reduction, has the advantage of low price, and has broad application prospects. ZD Wei and other studies of carbon from the air electrode catalyst MnO2, manganese nitrate solution of carbon black and the mixture heated calcination at different temperatures and found that at 340 ℃ was obtained when the catalyst MnO2 preferably at the same time to further study of the formation of Mn3O4 conducive to the reduction of oxygen to guide MnO2 crystal. T. Ohsaka, YL Cao and MnO2 as a catalyst for the reduction mechanism of oxygen has been studied. Currently, nanostructured catalyst MnO2 is a hot research topic. JS Yang and other studies amorphous MnO2 nano-catalysts for oxygen reduction performance, if 0.85mg/cm2 catalyst loading down the reaction of oxygen reduction current density can reach over 100mA/cm2. G. Zhang and other nano-structures for the synthesis of mesophase carbon particulate MnO2 composite catalyst, the catalyst nano-size that the network structure and active sites of the advantages of high density of the air electrode prepared catalytic reduction activity of oxygen was increased. sony VGP-BPS13/S sony VGP-BPS2A

 

3.1.2 catalyst for O2 in seawater

 

Oxygen dissolved in seawater as oxidant, due to low oxygen concentration, applied to the cathode must have good mass transfer properties, high surface area and high catalytic performance and long battery life because that the electrode should have good stability. Current research has revealed that the carbon fiber is a better cathode material. Hasvold such as bottle brush carbon fiber, it has a large surface area and mass transfer property, the preparation of the cathode of magnesium - dissolved oxygen in water fuel cells of the sea and half in 2W output power, the initial voltage to 1.4 V operating voltage to increase and stabilize after 15h at 1.6V, the voltage increase may be due to the surface of carbon fibers in a biofilm and marine improve its catalytic activity. Shen et al studied the use of Co3O4 / C than aluminum - water dissolved oxygen equipment cathode gas, conducted a test 70D, the results show that the use of Pt / C for Battery performance for a considerable, and voltage stability. sony VGP-BPS10 sony VGP-BPS2C

 

3.1.3 H2O2 catalyst

 

H2O2 reaction in the reaction at the cathode, including direct and indirect means. direct way is the direct reaction of H2O2 generated by electrochemical reduction of H2O or OH-; indirectly to first decompose H2O2 O2, O2 electrochemical reduction as a result of H2O or OH-. In practice, cell semi-fuel, the coexistence of two channels. directly to a more favorable, because the indirect channels, such as O2 production rate exceeds the rate of O2 consumption, and lead to excess accumulation of O2, the system pressure is increased, Exhaust system must be defined, resulting in cell structure, reducing the complexity and security. Therefore, the cathode of the H2O2 requirement is: (1) high catalytic activity, increased reaction speed and reduce the activation potential, (2) the direct electrochemical reduction of the high selectivity and reduce O2 production, (3) mass transfer properties, to reduce the concentration polarization. sony VGP-BPS18 sony VGP-BPS8A

 

The catalyst for the H2O2 has two main types, one is the charge in the carbon-based materials (such as carbon paper, carbon cloth and carbon fiber) or nickel foam on Pd, Ir, Ag and Au and other precious metals and their alloys prepared electrode. These electrodes have a good catalytic activity, and stability, but all catalytic decomposition of H2O2, the other is Fe and Co, Cu and porphyrin molecules triazine complex as a precursor of the carbon-loading of non-precious metal catalyst . The main problem of these catalysts is the stability of the poor.

 

3.2 negative

 

magnesium anode fuel cell is magnesium and magnesium alloys, but as an anode material of the battery of the following problems. Magnesium and magnesium alloys by volume aqueous hydrogen, which is the corrosion rate, which causes the loss of Congress and the rate of negative electrode capacity utilization; In addition, magnesium and alloy magnesium during the discharge process, there are still negative difference, which further increases the corrosion rate, which affects the discharge performance of fuel cell magnesium.

 

Currently, the solution of magnesium and magnesium alloy anode battery material as a problem mainly in developing new alloys, nano or micro structure of magnesium and magnesium alloys and magnesium and surface treatment magnesium alloy. sony VGP-BPS2B sony VGP-BPS9A/B

 

Development of new alloys, magnesium and other alloying elements be made of the binary, ternary alloy. On the one hand, the refinement of grain magnesium alloy, which increases the overvoltage of the hydrogen evolution reaction to decrease the rate of corrosion can destroy the passive film, and more complete, compact and passive in the porous film, easy to fall corrosion products, thus promoting the dissolution of the electrode activity and improve the electrochemical properties of magnesium alloys. At present, national and foreign researchers to develop new alloys has been studied in depth. The formation of magnesium and aluminum and zinc alloy of good performance, has the power of magnesium and a half for fuel cell submarines used in AZ31 magnesium alloy AZ61 and the United Kingdom Magnesium Elektron has developed AP65 and MT75 magnesium alloy, which is characterized with high potential, low hydrogen, in the mud less hydrogen emission rate of 0.15 ml? min-1? cm-2, the anode utilization rate of 84.6%, open circuit potential is -1.803 V (vs. SCE). solutions of sodium chloride, etc. [29] prepared alloys Mg-Ga-X ternary alloy with anodic polarization is small, low hydrogen, the corrosion products easy to fall in the mud less functionality . Deng Mei Hao [30] and if the study has added four elements (Pb, Sn, Ga, RE) on the electrochemical properties of magnesium alloy. MA-Qing Zheng [31], etc. added mg Hg, and alloys have been studied. Y. Feng, etc. added Hg Mg and Ga, Hg and Ga addition can improve the electrochemical properties of magnesium alloys as anode materials can improve the battery open circuit voltage. sony vgp-bps5a sony vgp-bps8

 

In addition, the formation of magnesium alloys magnesium added lithium batteries are significant things that other alloys of magnesium from the EMC point of view, adding even more intense than the lithium and magnesium, magnesium-lithium alloy can make a higher voltage and theoretical theoretical capacity. Currently, researchers have been conducted on Mg-Li alloys has been studied. DX Cao, Li-Mg alloy so different anode materials for the feasibility of magnesium underwater fuel cell for the alloy Mg-Li binary, and the addition of Al, Ce, Zn and alloying elements Mn such that the formation of multiple studies are conducted, the results suggest that unlike traditional versus Mg and AZ31, an alloy Mg-Li is an activity increasingly high electrochemical utilization. Indian researchers A.sivashanmugam of Mg-13Li alloy corrosion rates in different solutions and electrochemical behavior, and explore Mg-Li/MgCl2/CuO battery performance, the results show that the alloy with the classic Mg and Mg-Al ratio of Mg-13Li alloy offers greater capacity and use. Although the Mg-Li alloy as negative electrode materials for many, but Mg-Li alloy as the feasibility of fuel cell magnesium. sony vgp-bps2c sony vgp-bps5

 

With the development of nanotechnology, prepare magnesium and magnesium alloy in nano / micro structures, use of materials at a lower level to modify the physical and chemical properties, can improve the performance of fuel cell magnesium, WY Li, preparation etc. nano / micro structures of magnesium, magnesium used - air batteries, the current density obtained in 5mA/cm2 565Wh/Kg energy density. H. Grosjean, etc. using the micro structure prepared by grinding of magnesium and the electrochemical behavior, Mr. Zidoune such as electrochemical impedance spectroscopy study of electrochemical behavior before and after grinding, milling technology Yamamoto such as the use of magnesium and magnesium alloys Preparation of micro structure, and in his patent application is proposed magnesium - the feasibility of air cells. In short, if we can solve the milling process of oxidation of magnesium alloys and magnesium, as well as large-scale nano / micro structure of the technical problems of magnesium alloys, magnesium alloys to replace the zinc powder believed anode become qualified. sony vgp-bps2a sony vgp-bps2b

 

Surface treatment, Liu Jun-Quan process of plating on different treatment of magnesium alloy AZ91D the surface film, measured the processing time of both processes and characteristics of different discharge. Tests have shown that short time discharge nickel surface alloy flow above the copper surface and the blank sample.

 

3.3 electrolyte and additives

 

Currently, fuel cell electrolytic magnesium salts mainly sodium and magnesium as a simple neutral, as opposed to the wash if O2 and other oxidants in the neutral solution, a reaction rate slower reducing the magnesium fuel cell operating voltage, but the neutral solution, there are advantages, such as metal-air field in the neutral solution of sodium in the long term to avoid the carbonation in neutral solution of problems and more sure that the laundry.

 

In addition, as the use of battery anode materials and requirements of life, need to add solvent in the solution of magnesium alloy to improve performance as anode materials of the stack. There are two aspects of the role of additives, first need to add inhibitors of hydrogen in the electrolyte eFree Web Directory to reduce the excessive risk and self-corrosion, which reduces the corrosion rate of the use of anodes magnesium alloy, the other add the destruction of corrosion product of magnesium membrane activator, promoting the shedding of corrosion products, activated magnesium anode, to improve battery life. For example, DX Cao, as in the NaCl solution Ga2O3 added, allowing the use of magnesium-lithium alloy increased by 5%. However, there is an additive for fuel cell magnesium and its mechanism study the report very few people can learn from zinc and aluminum fuel cell electrolyte additives for fuel cell. sony vgp-bpl2 sony vgp-bps2

 

4 Outlook

 

fuel cells as a magnesium source high performance environmentally friendly, especially in the neutral magnesium salt or sea water system electrolyte fuel cell, with an excellent performance profitability. Through the development of various new magnesium alloy anode, cathode electrocatalyst and electrolyte additives and optimization of the cathode structure, so that the magnesium research on fuel cells could be advanced. magnesium fuel cells in portable electronics power, autonomous power operated vehicles, marine equipment submarines as the power supply and backup power, have very broad application prospects. sony vgp-bpl5a