In terms of supporting new energy vehicles, although Toyota will announce solid-state batteries this year, the prototype equipped with solid-state batteries will not be launched until 2022, and according to Toyota's plan, its mass production time will be around 2025. In the field of solid-state batteries, Toyota has a globally recognized leading edge. According to public information, Toyota currently holds more than 65,438+0,000 patents related to solid-state batteries.
In fact, compared with the liquid lithium battery we use now, car companies have already set foot in the research and development of solid-state batteries, trying to solve the problems faced by liquid lithium batteries in another unique form. Therefore, solid-state batteries are also recognized as the next generation power batteries, which will replace liquid electrolyte lithium-ion batteries. At present, many related companies, including Amperex Technology Co, Limited, BYD and Guo Xuan Hi-Tech, claim to have in-depth research in this field, and even many enterprises and universities have participated in the research and development of solid-state batteries, such as Daimler, Fisco, China lithium battery giant, French oil company Total and derivatives of MIT and Stanford University.
From the perspective of development prospects, solid-state batteries seem to be very attractive, but from the perspective of application, will solid-state batteries really be the most suitable energy carrier for electric vehicles? And if solid-state batteries are really popular, can they bring a real explosion era to electric vehicles?
At present, the most obvious shortcomings of liquid electrolyte lithium batteries we can see are the potential safety hazards caused by instability, and the obvious impact of performance degradation on driving in different environments, such as spontaneous combustion of batteries and sharp decline in endurance in winter. These are the core problems faced by liquid electrolyte lithium batteries at present. The advantage of solid-state batteries lies in filling these shortcomings of liquid batteries.
The spontaneous combustion of electric vehicles that we usually see occurs when charging. The main reason for this problem is that the growth of lithium dendrite in liquid electrolyte battery is easy to puncture the separator during charging, resulting in short circuit of the battery, unstable internal structure change and spontaneous combustion. Moreover, based on the movement characteristics of the electrolyte, the viscosity of the electrolyte will increase and the ion conduction speed will slow down in the low temperature environment, which will lead to the mismatch of the electron migration speed of the external circuit, so the battery will be seriously polarized and the charge and discharge capacity will drop sharply, which is also the reason why the electric vehicle will have serious power loss in the extremely cold area.
In contrast, solid-state batteries do not have the troubles of the above-mentioned liquid batteries, mainly because solid-state batteries are essentially different from liquid batteries in structure. Traditional lithium batteries have positive and negative electrodes at both ends and electrolyte (liquid) in the middle. During the movement of lithium ion from the positive electrode to the negative electrode and then to the positive electrode, the charging and discharging process of the battery is completed. Solid-state battery is a kind of battery using solid electrode and solid electrolyte, which can inhibit lithium dendrite, is not easy to burn, explode, leak electrolyte and have no side effects at high temperature, which means that solid-state battery can perfectly avoid the influence of liquid electrolyte and become a safer capacitor carrier.
Moreover, the energy density of solid-state batteries is higher. For ordinary liquid batteries, the maximum can generally reach 300 Wh/kg, but it is considered impossible to exceed 500 Wh/kg. However, the solid-state battery can directly use metal lithium as the negative electrode instead of graphite negative electrode embedded with lithium, which can greatly reduce the amount of negative electrode materials and obviously improve the energy density of the whole battery. The energy density provided by the research and development of solid-state batteries can basically reach 300-400 Wh/kg, and its starting point is the end point of liquid batteries, which can be said to have considerable development potential, which is why solid-state batteries are also considered as ideal batteries for electric vehicles.
Compared with the shortcomings in performance, the reason why solid-state batteries need to enter the market as soon as possible is to fill another major problem of liquid electrolyte lithium batteries-life. According to the data of China Automotive Technology Research Center, in 2020, more than 200,000 tons of power batteries will be retired in China. If these lithium batteries are not handled properly, it will cause environmental pollution for 50 years. At this time, there will be two very important problems. First, with the continuous circulation of electric vehicles in the market, the market share of liquid electrolyte lithium batteries will only increase, and based on its short life (a pure electric vehicle conservatively predicts that the battery will decay below 80% in 5-7 years and enter the scrapping stage), the scrapped liquid electrolyte lithium batteries will only increase year by year, and their processing pressure will only increase year by year.
Secondly, based on the recycling ability of these liquid electrolyte lithium batteries, battery recycling needs to be disassembled, refurbished and assembled into new power batteries before being reloaded into electric vehicles, and the cost generated in this process is undoubtedly huge. But of course, some people say that power battery recycling is a new blue ocean derived from electric vehicles, but if solid-state batteries with stronger liquidity enter the market, the battery life of electric vehicles will be significantly improved (ideally, solid-state batteries can be recycled for about 45 thousand times). Recycling the blue ocean from power batteries may have a great impact.
In fact, in terms of battery characteristics, the benefits of solid-state batteries are also obvious. The most important thing is that solid-state batteries solve the two core problems of reliability and charging efficiency of today's electric vehicles, which is also the core concern of consumers when choosing electric vehicles. Moreover, from the deep-seated reasons of endurance anxiety, if Toyota's solid-state battery can really fill the battery from empty within 10 minutes, it will basically fill the gap in the renewal of electric vehicles and fuel vehicles, which is undoubtedly the biggest impact of electric vehicles on fuel vehicles.
Moreover, judging from the new energy strategies of countries around the world, many countries now put the ban on the sale of fuel vehicles on the agenda. The basic planning time is between 2025 (Netherlands, Norway), 2030 (United States (California), Germany, India) and 2040 (France, Britain). Toyota's solid-state battery will be used in real vehicles in 2025, and it will also step on the earliest fuel.
Whether the electric car is good or not is still too early to say. Because for electric vehicles, there is still considerable development potential, which is why new energy vehicles can still attract a large wave of investment and attention even when the technology is not fully mature. However, it is worthy of recognition that the new era of new energy vehicles will change the future pattern of the automobile industry, and perhaps the arrival of solid-state batteries will be another opportunity to lead the outbreak of this industry.