From the perspective of environmental protection, the pollution problem of lead-acid batteries is unavoidable. Lead plates and sulfuric acid solution of lead-acid batteries are difficult to degrade pollutants. The safety of lead-acid batteries and the impact of battery attenuation on the mileage are also headaches for the stadium. Take two golf carts as an example. Common golf carts on the market are equipped with six 175Ah lead-acid batteries.
A new car equipped with this battery has a cruising range of approximately 40Km after being fully charged. However, as the caddy's use time increases, the charging and discharging capacity of the battery will get worse and worse, even less than 10km. The reduction in cruising range will greatly affect the normal use of golf carts. These problems of lead-acid batteries cannot be solved from a technical point of view. However, the emergence of lithium batteries is a glimpse, replacing lead-acid power batteries with lithium batteries has become the inevitable development direction of golf cart batteries.
As an enterprise engaged in the development, production and sales of golf carts for many years, it has done in-depth research on lithium batteries. Here, we share some knowledge and give a brief introduction to the technology and advantages of using lithium battery in the golf cart.
Introduction to the types and characteristics of lithium batteries:
At present, lithium batteries can be divided into three types: lithium manganate, lithium iron phosphate, and ternary materials.
Lithium manganate is one of the more promising lithium ion cathode materials. Compared with traditional cathode materials such as lithium cobalt oxide, lithium manganese oxide has the advantages of rich resources, low cost, no pollution, good safety, and good rate performance. It is an ideal power battery cathode material, but its poor cycle performance and electricity The chemical stability greatly limits its industrialization.
Lithium iron phosphate has only appeared in recent years as a material for lithium power batteries. The domestic development of large-capacity lithium iron phosphate batteries was about 2005. Its safety performance and cycle life are unmatched by other materials, and these are also the most important technical indicators of power batteries. The 1C charge-discharge cycle life of a single battery reaches 2000 times. Single-cell battery will not burn or explode when overcharged at 30V. Lithium iron phosphate cathode materials make large-capacity lithium-ion batteries easier to use in series to meet the needs of frequent charging and discharging of electric vehicles.
Lithium iron phosphate has the advantages of non-toxic, non-polluting, good safety performance, wide source of raw materials, low price, and long life. It is an ideal cathode material for a new generation of lithium-ion batteries.
Lithium iron phosphate batteries also have their disadvantages. For example, the tap density of the lithium iron phosphate cathode material is relatively small. The volume of the lithium iron phosphate battery of equal capacity is larger than that of lithium cobalt oxide and other lithium ion batteries, so it does not have an advantage in miniature batteries. Due to the inherent characteristics of lithium iron phosphate materials, its low temperature performance is inferior to other cathode materials such as lithium manganate. In general, for a single cell (note that it is a single cell and not a battery pack, for the battery pack, the measured low temperature performance may be slightly higher, which is related to the heat dissipation conditions), its capacity at 0°C is maintained The rate is about 60 to 70%, 40 to 55% at -10°C, and 20 to 40% at -20°C. Obviously, such low temperature performance cannot meet the requirements of power supply.
Lithium iron phosphate batteries have consistency problems. The life of single lithium iron phosphate battery currently exceeds 2000 times, but the life of the battery pack will be greatly reduced, possibly 500 times. Because the battery pack is made up of a large number of single batteries in series, its working condition is like a group of people running together with a rope. Even if everyone is a sprinter, if everyone’s movements are not consistent, the team will not run fast. The speed is even slower than that of the slowest individual runner. The battery pack is the same. Only when the battery performance is highly consistent, can the life span be close to the level of a single battery. Therefore, the battery is not suitable for high-voltage or large-capacity vehicles.
Ternary polymer lithium battery refers to a lithium battery that uses lithium nickel cobalt manganese ternary cathode material as its cathode material. There are many kinds of cathode materials for lithium-ion batteries, mainly lithium cobalt oxide, lithium manganate, lithium nickelate, ternary materials, lithium iron phosphate and so on. Ternary materials combine the advantages of lithium cobalt oxide, lithium nickel oxide, and lithium manganate materials. They have excellent characteristics such as high capacity, low cost, and good safety. They gradually occupy a certain market share in small lithium batteries and are The field of power lithium battery has good development prospects.
For lithium batteries, cobalt metal is an indispensable material. However, on the one hand, metal cobalt is expensive, and on the other hand, it is toxic. In recent years, both Japanese and Korean companies with leading technology and domestic battery manufacturers have been committed to the "less cobalt" of batteries. Under this trend, nickel cobalt lithium manganate ternary materials prepared from nickel salt, cobalt salt, and manganese salt are gradually being respected. From the perspective of chemical properties, ternary materials are transition metal oxides, and the energy density of the battery is relatively high.
Although the role of cobalt is still indispensable in ternary materials, the mass fraction is usually controlled at about 20%, and the cost is significantly reduced. It also has the advantages of lithium cobalt oxide and lithium nickel oxide. From electric vehicles to smart phones, wearable devices or power banks, this new technology is fully applicable. Tesla was the first to apply ternary batteries to electric vehicles. ModelS has a cruising range of 486 kilometers and a battery capacity of 85kWh. It uses 8142 3.4AH Panasonic 18650 batteries. Engineers evenly distribute these batteries one by one in the form of bricks and slices to form a whole battery pack, which is located on the underbody of the vehicle body.
In terms of battery power and safety, it is best to mount a ternary battery on a golf cart.
From theoretical calculations and actual tests, it is concluded that the Japanese Panasonic ternary lithium battery used in Tesla cars has excellent performance and is suitable for use in golf carts.
In addition to automobiles, a large number of lithium batteries are used in power equipment such as telecommunication base stations, and lithium battery technology is already very mature. With the mass production of lithium batteries, the cost of lithium batteries is also falling.
It is still very difficult and challenging technically to mount lithium batteries on golf carts. Specifically, the difficulty lies in how to control the consistency of lithium batteries, the degree of intelligent matching of the power management system (BMS), and the matching of the charger charging curve with the charging curve of the lithium battery. Lithium batteries work more delicately. For example, the power display of lithium batteries is controlled by electrical signals, while lead-acid batteries reflect the power by changes in actual voltage. For another example, there must be a communication protocol between the lithium battery charger and the lithium battery management system. This requires the matching of various components in the lithium battery system to be done well, if it is not done well, it will affect the normal operation of the lithium battery. In addition, due to the high density, small size, and light weight of lithium batteries, golf carts that match lithium batteries need to be redesigned, instead of simply loading lithium batteries on existing golf carts. First, select a battery with a suitable capacity according to the working requirements of the cruising range, and then determine the battery volume and weight, and finally use this to optimize the design of the golf's chassis suspension. By continuously adjusting and optimizing the hardness of the damping spring, the best comfort is finally achieved.
The actual performance and performance of the lithium battery version of the golf cart is still commendable. First, the cost of one-time input of lithium battery golf carts will be relatively high, but compared with the comprehensive cost of lead-acid batteries and lithium batteries during the life cycle of the golf carts, the lithium battery golf carts are still relatively economical. Based on the calculation of the service life of 5-6 years, lithium battery does not need to be replaced in the middle, while lead-acid battery needs to be replaced in about two years. In addition, the daily maintenance cost of lead-acid battery is very high, and battery fluid needs to be added frequently. Once the maintenance is not in place, the lead-acid battery can be easily damaged. The cost and maintenance cost of replacing lead-acid batteries are much higher than that of using lithium batteries.
Second, the attenuation of the lithium battery is small, and the vehicle can be used frequently. The attendance rate of the vehicles is much higher than that of the lead-acid version of the golf carts, and the stadium can be used less vehicles. The maintenance of the lithium battery version of the vehicle is simple and labor-saving, no need to add battery fluid frequently, saving labor and materials. In addition, because the lithium battery vehicles are relatively light, the tires, shock absorbers, brakes and other parts of the vehicle wear much less.
In short, lithium battery technology is becoming more mature. In terms of technology and performance, the performance of the lithium battery version of the golf cart will be much better than that of the lead-acid vehicle. The reason why there is no mass use is the technical bottleneck and cost constraints, as well as people's habits. This requires relevant R&D personnel to work hard and solve problems persistently, and it also requires people to continue to accept new things. Observing more and more electric vehicles on the street and reviewing the development history of gasoline vehicles, facts have proved that electrification of vehicles is an irreversible trend. Lithium battery golf carts are also a development trend. In the future, more and more lithium battery golf carts will serve the majority of golf courses.