In the new energy vehicle industry, technical problems such as difficulty in charging and long charging time have always been one of the obstacles to the promotion of electric vehicles. In the case that the charging facilities cannot fully meet the demand, the core problem of all this is that the charging technology of electric vehicles is not good enough to meet the requirements of fast charging. Power vehicles that can meet fast charging have become an obvious demand in the industry.

　　However, new market demands will inevitably lead to the emergence of new technological innovations and products in all walks of life.

　　"The second-generation fast-charging lithium battery we released this time can shorten the charging time to 15 minutes." At the 2013 3rd China (Shenzhen) Public Transport City Development Forum, Zheng Zhuoqun, Director of the Technology Center of Weihong Power System Co., Ltd. introduced In the current situation that the general charging technology of new energy vehicles cannot meet the requirements of fast charging, the industry needs to make changes. Advanced power battery technology According to Comrade Zhiming, general manager of Weihong Power (Huzhou) System Co., Ltd., Weihong Power’s first-generation fast-charging battery product-LpTO? Lithium titanate battery has accumulated more than 900 buses in operation. 60 million kilometers. While the second-generation product released this time still retains the characteristics of fast charging and long cycle life of more than 10,000 times, its energy density and economy have been significantly improved compared with the previous generation products. It provides a better energy solution for bus operation of pure electric buses.

　　"The cycle life of the multi-element composite lithium battery cell is still more than 10,000 times at room temperature when charged and discharged at a rate of 6C, which is twice that of the world's best lithium iron phosphate battery products. After being assembled, it can meet the charging rate of 4C. It means that the battery pack can be fully charged within 15 minutes." Zheng Zhuoqun said that the weight energy density of the multi-element composite lithium battery has also reached 120Wh/kg, which exceeds that of lithium titanate and lithium iron phosphate batteries. The discharge capacity of the multi-element composite lithium battery at low temperatures (minus 20 degrees Celsius) can reach 78% of the normal temperature, and it has good low temperature performance.

　　The launch of multi-element composite lithium battery products has made up for the shortcomings of fast-charging lithium titanate batteries with low energy density and energy-type lithium iron phosphate and ternary batteries that cannot be fast-charged, providing pure electric vehicle products to truly meet the actual needs of bus operations. Innovative, more feasible, and more economical solutions.

　　"The improvement of product performance comes from the research and development of basic raw materials." Comrade Zhiming told reporters that the multi-element composite lithium battery uses the porous composite carbon of Weihong's patented technology as the negative electrode material. The increased specific surface area and pores also greatly increase the number of lithium ion migration and insertion channels, allowing lithium ions to be inserted and extracted quickly and stably. This solves the long-term technical bottleneck hindering the rapid charging of high-energy density graphite negative lithium battery products, and at the same time greatly extends the battery life.

　　This technology also greatly improves the battery safety compared to traditional graphite anode lithium batteries. The multi-element composite lithium battery group has passed the mandatory inspection by the National Passenger Car Quality Supervision and Inspection Center. The inspection test includes 9 safety tests including short circuit, overcharge, over discharge, heavy object impact, drop, squeeze, acupuncture, height simulation, heating, etc., in full compliance with the national QC/T743-2006 "Lithium for Electric Vehicles" "Ion battery" safety standard.

　　The characteristics of fast charging

　　"Slow charging and long time-consuming are common problems encountered by most electric vehicles that are still in operation." Comrade Zhiming believes that the biggest difference between Weihong and other power battery companies is that they have a deep understanding of bus users' ability to solve the technical bottlenecks of pure electric buses and improve operations. The demand for efficiency, and the use of its own development capabilities in the field of basic material chemistry, actively seek more feasible solutions for first-line public transport users.

　　is different from the lithium iron phosphate pure electric vehicle which needs to be equipped with all-day batteries, and the lithium titanate pure electric vehicle needs to frequently enter the station for charging. The use of multi-element composite lithium batteries only needs to carry the batteries required for half a day of operation. After the operation in the morning, a quick recharge of 15 minutes in the noon can meet the full-time operation of the whole day.

　　The new generation of multi-element composite lithium battery has a higher energy density, which makes the vehicle's driving range longer, and at the same time the battery weight is reduced by 40%.

　　Traditional lithium iron phosphate battery packs cannot be charged quickly, and buses need to be equipped with batteries required for all-day operations. The on-board battery pack weighs more than 4 tons; however, the multi-element composite lithium battery technology that can be quickly charged requires only half-day on-board batteries. The weight can be reduced by 40% compared with the lithium iron phosphate solution, which significantly reduces the structural load and energy consumption of the car body, improves safety, and increases the passenger capacity. Can still charge quickly, improve efficiency and have long cycle life

　　"The same fast charging effect does not require frequent return to the station for charging. All day operations only need to use the fast charging 15 minutes to recharge once during the noon break; when returning to the station at night, you can choose fast charging or slow charging using grid power." Comrade Zhiming believes that multi-element composite batteries have a long service life and less investment in vehicles and charging facilities, which can achieve high-efficiency operations and maximize economic benefits.

　　As an active implementer of fast charging technology, Weihong Power System has launched large-scale field operations for fast charging vehicles at home and abroad since Weihong launched the first generation of fast charging batteries in early 2011. As of September 2013, Weihong's fast rechargeable battery system products have been equipped with more than 900 public buses, achieving practical operation accumulation of nearly 60 million kilometers.

　　It is understood that the fast charging station set up in the Chongqing Airport Bus Hub can quickly charge 6 pure electric fast charging buses at the same time, and the battery pack can be fully charged in 6-8 minutes; more than two years of field operations are fast Charging technology, especially the profound experience accumulated in the application of public transportation, has also been recognized by public transportation customers.

　　"The release of the second-generation fast-charging lithium battery marks another breakthrough for Weihong in this technology. Higher energy density, fast charging, and long cycle life have made the current bottleneck of electric vehicles a breakthrough. We will very much look forward to this new product to accelerate the process of electrification of transportation." For future plans, Comrade Ming said that the inflection point of technology leading the market has begun to highlight, and now it depends on who can grasp it.