日前，宁德时代首席科学家吴凯在CIBF上表示，如果用技术和制造成熟度作为评价体系(以1-9打分)，宁德时代的全固态电池研发目前处于4分的水平。吴凯称，宁德时代的目标是到2027年达到7-8分的水平，“2027年，宁德时代全固态电池小批量生产机会很大，但受成本等因素制约，大规模生产尚不能实现。”

　　事实上，在此之前，宁德时代董事长曾毓群已经两次就全固态电池表态。今年3月，在接受机构调研时，宁德时代董事长曾毓群表示，前沿技术的落地要经历3个路线，即技术路线、产品路线、商品路线。首先看在技术上是否成立、能否打通;其次，变成产品之后，在生产制造过程中安全性、可靠性、一致性、质量是否能保证;第三，是否能卖出去，因为太贵了可能会卖不动。

01

对全固态电池的关注升温

　　固态电池有3条技术路线，即氧化物路线、硫化物路线、及聚合物路线。“目前还有很多基本的科学问题待解决，如大多数固态电解质中的离子扩散速率与液态电解质存在数量级差异、固固界面难以始终保持良好接触等，在突破这些科技问题后，还会遇到产业化的问题。”曾毓群表示。

　　同月，曾毓群在接受英国《金融时报》采访时也指出，日本汽车制造商等鼓吹的电动汽车固态电池距离商业化还有数年时间，这项技术还不够完善，缺乏耐用性，且仍然存在安全问题(比如电池在车祸中破裂导致的后果等)。

　　可以看出，吴凯上月对于全固态电池的表态，已经是宁德时代今年第三次公开就全固态电池的产业化表态。

　　今年以来，对全固态电池的关注和热议从国外传入国内。对于国外企业来说，希望通过全固态电池实现弯道超车，赶超中国在动力电池领域的优势;对于国内企业来说，如何巩固和引领在动力电池领域的产业、技术优势，政府和头部企业也同样很重视。

　　全固态电池之所以成为国内外企业押注的核心路线，在于其能够在超高安全保证的前提下较大幅度的提升能量密度，从而实现极致性能，可以满足更多场景的应用需求，实现对现有电池体系的颠覆。

　　在全球进行全固态电池竞逐的大环境下，宁德时代也不得不表示，“公司(宁德时代)非常重视固态电池，已经进行了多年的布局，最近加大了很多投入。”

　　需要指出的是，宁德时代在全固态电池产业化时间表上，仍然较为冷静。

　　吴凯认为，要实现全固态电池产业化，仍需要解决固固界面、锂金属负极应用、硫化物电解质在空气中不稳定和合成成本较高，以及全固态电池生产工艺等四大难题。

　　事实上，上述四个难题，目前没有一个可以很好地得到解决。

　　以固固界面的问题为例，正极材料与电解质之间固固界面接触不充分，阻碍离子传输;负极在充放电过程体积膨胀大，导致固-固界面的动态损伤，难以修复，持续恶化固-固界面……这些都严重影响全固态电池的循环寿命和倍率性能。

　　全固态电池要实现500Wh/kg、1000Wh/L的高能量密度目标，电池负极以目前的技术看必须用锂金属，但锂金属有两个问题：巨大的体积膨胀和枝晶生长。此外，全固态锂金属电池还有一个瓶颈需要突破，那就是电池循环次数的提升。据中科院院士欧阳明高介绍，目前500Wh/kg的锂金属电池大概只有几十次的循环寿命，还要做大量的工作。此外，在快充和安全性方面，因为锂金属熔点只有180摄氏度，这些都需要攻关。

　　由此可见，全固态电池的研发和量产是一项非常艰巨复杂的工程。宁德时代针对固态电池已经有十余年的研发积累，目前已经组建了一支近千人的全固态电池研发团队，也取得了一些进展和经验。吴凯表示，从全固态电池的技术成熟度和制造成熟度来看，有望在未来3年逐步进入成熟期，真正开启量产化进程。

02

半固态路线有必要有意义

　　相比国外直接押注全固态电池，国内企业现阶段则重点以半固态(固液混合)为特色，产业链完整，企业正尝试装车配套。业内人士认为，产生这种局面的原因，主要是中国在液态电池技术路线上技术成熟，产业链非常完善，且下游应用场景比较多元。

　　欧阳明高认为，作为过渡技术路线，国内发展半固态电池有必要有且意义。

　　事实上，半固态电池近年来在国内已经被广泛推进，且卓有成效。

　　目前包括亿纬锂能、孚能科技、力神电池、清淘能源、卫蓝新能源、正力新能、比克电池、国轩高科、赣锋锂电等多家企业，都已经将半固态电池推向了产业化阶段。

　　近日，比克电池透露，公司预计今年7月将具备半固态电池的交付能力。据悉，比克半固态锂电池采用聚合物+氧化物的复合体系，通过固态电解质掺混和原位固化技术，形成电解液含量在10%以内的半固态电池，“这种技术路线下的能量密度可达到350Wh/kg以上，呈现高能量、高安全、低膨胀、低内阻、宽温区的特性。”

　　据比克电池介绍，公司正不断优化半固态体系，目前能量密度可达到360Wh/kg。同时，比克电池正规划将金属锂负极应用到半固态电池体系，计划在2024年底将能量密度提升至450Wh/kg。

　　上个月，正力新能发布了双重半固态超长续航大圆柱电池。据悉，正力新能研发了超高镍正极材料的固态电解质表面修饰技术和固态电解质复合隔膜技术。得益于此，大圆柱电芯的失效起始温度提升10°C，失效最高温度降低150°C。功率性能改善上，零下20°C 低温功率提升了20%。

　　据介绍，正力新能46系列大圆柱电芯采用超高镍正极+高硅负极的材料体系，使得动力电池系统能量密度超245Wh/kg，整包电量高达 170kWh，支持纯电MPV车型，满电续航1000公里以上。

　　日前，亿纬锂能透露，公司固液混合的半固态体系，目前已完成了部分产品开发。基于50Ah软包半固态电池，可实现330Wh/Kg的能量密度，循环寿命超过2000次。

　　清陶能源的半固态电池由复合正极、复合负极、电解质和电解质隔膜组成，仍有注液环节，液体比例大概在5%-15%，今年将配套智己L6装车上市销售。

　　据孚能科技介绍，其第一代半固态电池已顺利量产装车;下一代半固态产品已具备量产条件，具有更高能量密度，适用于乘用车、低空飞行等新兴领域。

　　力神电池透露，公司于今年1月完成全新一代半固态电池开发，能量密度达402Wh/kg。据介绍，该产品兼顾高能量密度和高安全性能，采用新型集成设计技术，通过调控电化学工艺制式抑制过渡金属溶出和结构错位生长，实现半固体电池的超轻量化和高安全。据悉，该产品未来将主要瞄准超长续航中高端电动汽车，以及eVTOL(电动垂直起降飞行器)等领域。

　　从技术成熟度和产业化进程来看，中国在液态、半固态电池领域已经实现了引领，尤其是半固态电池预计在接下来两三年内会实现批量配套应用，继续在高安全、高能量密度等维度上实现引领。

　　相较于中国，日本和欧美在液态、半固态电池方面处于落后地位。其发展全固态电池的目标，在于颠覆中国在液态锂电池方面的优势。“我们要保优势、防颠覆，攻克全固态，兼顾优化液态锂离子电池。我们不能扔液态锂离子电池，液态锂离子电池是我们的优势强项，今后几十年还要靠这个吃饭。”欧阳明高说。实际上，全固态电池的颠覆风险业界都心里有数，无论是对于现在的头部电池企业如何巩固优势堡垒，还是应对海外企业的竞争，全固态电池的研发都会被迫提速。

Under the high attention and hype in the market, CATL, as a global leader in power batteries, cannot avoid discussing solid-state batteries.

The development of all solid-state batteries is forced to accelerate

Recently, Wu Kai, Chief Scientist of CATL, stated at CIBF that if technology and manufacturing maturity are used as evaluation criteria (on a scale of 1-9), CATL's research and development of all solid state batteries is currently at a level of 4. Wu Kai stated that CATL's goal is to achieve a score of 7-8 by 2027. "In 2027, CATL has great opportunities for small-scale production of all solid state batteries, but due to cost constraints and other factors, large-scale production cannot be achieved yet."

In fact, prior to this, Zeng Yuqun, Chairman of CATL, had already made two statements regarding all solid-state batteries. In March of this year, during an institutional survey, Zeng Yuqun, Chairman of CATL, stated that the implementation of cutting-edge technology needs to go through three routes: technology route, product route, and commodity route. Firstly, check whether the technology is established and whether it can be connected; Secondly, after becoming a product, can safety, reliability, consistency, and quality be guaranteed during the production and manufacturing process; Thirdly, whether it can be sold, as it may be too expensive to sell.

01

The increasing attention to solid-state batteries

There are three technological routes for solid-state batteries, namely oxide route, sulfide route, and polymer route. "There are still many basic scientific problems to be solved, such as the order of magnitude difference in ion diffusion rate between most solid electrolytes and liquid electrolytes, and the difficulty in maintaining good contact between solid and solid interfaces. After breaking through these technological problems, industrialization will also be encountered," said Zeng Yuqun.

In the same month, Zeng Yuqun also pointed out in an interview with the Financial Times that Japanese car manufacturers and others are still several years away from commercializing solid-state batteries for electric vehicles. This technology is not yet perfect, lacks durability, and still has safety issues (such as the consequences of battery rupture in car accidents).

It can be seen that Wu Kai's statement last month regarding the industrialization of all solid state batteries was the third public statement made by CATL this year.

Since the beginning of this year, attention and discussion on solid-state batteries have been introduced from abroad to China. For foreign companies, they hope to achieve overtaking on curves through all solid state batteries, catching up with China's advantages in the field of power batteries; For domestic enterprises, the government and leading enterprises also attach great importance to consolidating and leading their industrial and technological advantages in the field of power batteries.

The reason why all solid state batteries have become the core route of investment for domestic and foreign enterprises is that they can significantly improve energy density while ensuring ultra-high safety, thereby achieving ultimate performance, meeting the application needs of more scenarios, and achieving the overturning of existing battery systems.

In the global competition for all solid-state batteries, CATL has to say, "The company (CATL) attaches great importance to solid-state batteries and has been laying out for many years, recently increasing a lot of investment."

It should be pointed out that CATL is still relatively calm in its schedule for the industrialization of all solid state batteries.

Wu Kai believes that in order to achieve the industrialization of all solid state batteries, it is still necessary to solve four major problems: solid solid interface, application of lithium metal negative electrode, instability and high synthesis cost of sulfide electrolyte in air, and production process of all solid state batteries.

In fact, none of the above four difficult problems can be effectively solved at present.

Taking the issue of solid solid interface as an example, insufficient contact between the positive electrode material and the electrolyte hinders ion transport; The volume expansion of the negative electrode during the charging and discharging process leads to dynamic damage to the solid-solid interface, which is difficult to repair and continuously deteriorates the solid-solid interface... These seriously affect the cycle life and rate performance of all solid state batteries.

To achieve high energy density goals of 500Wh/kg and 1000Wh/L in all solid state batteries, lithium metal must be used as the negative electrode based on current technology. However, lithium metal has two problems: huge volume expansion and dendritic growth. In addition, there is a bottleneck that needs to be overcome for all solid state lithium metal batteries, which is the increase in battery cycle times. According to Academician Ouyang Minggao of the Chinese Academy of Sciences, the current 500Wh/kg lithium metal battery only has a cycle life of about a few dozen times, and a lot of work needs to be done. In addition, in terms of fast charging and safety, as the melting point of lithium metal is only 180 degrees Celsius, these need to be tackled.

It can be seen that the research and mass production of all solid state batteries is a very difficult and complex project. Ningde Times has more than ten years of research and development experience in solid-state batteries. Currently, it has formed a research and development team of nearly a thousand people for all solid-state batteries, and has made some progress and experience. Wu Kai stated that from the perspective of the technological and manufacturing maturity of all solid state batteries, it is expected to gradually enter a mature period in the next three years and truly start the mass production process.

02

The semi-solid route is necessary and meaningful

Compared to foreign direct bets on all solid state batteries, domestic enterprises are currently focusing on semi-solid (solid-liquid mixture) as their characteristic, with a complete industrial chain, and are trying to install supporting vehicles. Industry insiders believe that the main reason for this situation is that China has mature technology in the field of liquid battery technology, a very complete industrial chain, and diverse downstream application scenarios.

Ouyang Minggao believes that as a transitional technology route, it is necessary and meaningful to develop semi-solid state batteries in China.

In fact, semi-solid state batteries have been widely promoted and have achieved remarkable results in China in recent years.

At present, multiple enterprises including Yiwei Lithium Energy, Funeng Technology, Lishen Battery, Qingtao Energy, Weilan New Energy, Zhengli New Energy, Bike Battery, Guoxuan High tech, and Ganfeng Lithium have all pushed semi-solid batteries to the industrialization stage.

Recently, Bike Battery revealed that the company expects to have the delivery capacity for semi-solid batteries by July this year. It is reported that the Bike semi-solid lithium battery adopts a composite system of polymer and oxide, and forms a semi-solid battery with an electrolyte content of less than 10% through solid-state electrolyte mixing and in-situ solidification technology. "The energy density under this technology route can reach over 350Wh/kg, presenting characteristics of high energy, high safety, low expansion, low internal resistance, and wide temperature range."

According to Bike Battery, the company is continuously optimizing its semi-solid system, with an energy density of up to 360Wh/kg. At the same time, Bike Battery has officially planned to apply metal lithium negative electrodes to semi-solid battery systems, with plans to increase energy density to 450Wh/kg by the end of 2024.

Last month, Zhengli New Energy released a dual semi-solid ultra long endurance cylindrical battery. It is reported that Zhengli Xinneng has developed solid-state electrolyte surface modification technology and solid-state electrolyte composite separator technology for ultra-high nickel cathode materials. Thanks to this, the initial failure temperature of the large cylindrical battery cell increased by 10 ° C, and the maximum failure temperature decreased by 150 ° C. In terms of power performance improvement, the low-temperature power at minus 20 ° C has increased by 20%.

It is reported that the Zhengli New Energy 46 series large cylindrical battery cells adopt a material system of ultra-high nickel positive electrode and high silicon negative electrode, which makes the energy density of the power battery system exceed 245Wh/kg, and the total battery capacity can reach up to 170kWh. It supports pure electric MPV models, with a full charge range of over 1000 kilometers.

Recently, Yiwei Lithium revealed that the company has completed the development of some products for its solid-liquid mixed semi-solid system. Based on a 50Ah soft pack semi-solid state battery, it can achieve an energy density of 330Wh/Kg and a cycle life of over 2000 times.

The semi-solid battery of Qingtao Energy is composed of a composite positive electrode, a composite negative electrode, an electrolyte, and an electrolyte separator. There is still a liquid injection process, with a liquid ratio of approximately 5% -15%. This year, it will be equipped with the Zhiji L6 and put on the market for sale.

According to Funeng Technology, its first generation semi-solid battery has been successfully mass-produced and installed in vehicles; The next generation of semi-solid products is ready for mass production, with higher energy density, suitable for emerging fields such as passenger cars and low altitude flight.

Lishen Battery revealed that the company completed the development of a new generation of semi-solid batteries in January this year, with an energy density of 402Wh/kg. It is reported that this product combines high energy density and high safety performance, adopts new integrated design technology, and suppresses transition metal dissolution and structural dislocation growth by regulating the electrochemical process, achieving ultra lightweight and high safety of semi-solid batteries. It is reported that the product will mainly target high-end electric vehicles with ultra long endurance in the future, as well as eVTOL (electric vertical takeoff and landing aircraft) and other fields.

From the perspective of technological maturity and industrialization process, China has achieved leadership in the field of liquid and semi-solid batteries, especially in the next two to three years when semi-solid batteries are expected to achieve mass supporting applications, continuing to lead in high safety, high energy density and other dimensions.

Compared to China, Japan and Europe and America are in a backward position in liquid and semi-solid batteries. The goal of developing all solid state batteries is to overturn China's advantages in liquid lithium batteries. "We need to maintain our advantages, prevent subversion, conquer all solid-state, and optimize liquid lithium-ion batteries. We cannot throw away liquid lithium-ion batteries. Liquid lithium-ion batteries are our strengths and will continue to rely on them for decades to come," said Ouyang Minggao. In fact, the industry has a clear understanding of the disruptive risks of all solid state batteries. Whether it is how the current top battery companies can consolidate their advantages or cope with competition from overseas enterprises, the research and development of all solid state batteries will be forced to accelerate.