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According to overseas media outlet Autocar, Toyota Executive Vice President and Chief Technology Officer Shigeki Terashi revealed on the eve of the Tokyo Motor Show that Toyota will launch a new energy vehicle equipped with solid-state battery technology during the 2020 Tokyo Olympics.

It is reported that this vehicle model will be developed based on Toyota's e-Palette platform, a concept product Toyota has created with an eye toward the future of autonomous driving and connected car technologies. According to earlier announcements from Toyota, the e-Palette will serve as a shuttle bus transporting athletes and support staff during the 2020 Tokyo Olympics and Paralympics.

High costs are impacting the commercialization process.

Compared to existing new-energy products equipped with lithium iron phosphate or ternary lithium power batteries, solid-state batteries boast a significantly higher energy density, and their flexible characteristics also enable more diverse battery designs. Additionally, solid-state batteries offer enhanced safety advantages. However, due to limitations in technology and cost, large-scale production of solid-state batteries remains highly challenging at present.

Shimajima Shigeki also stated that Toyota's launch of a new energy vehicle equipped with solid-state batteries aims to showcase the company's technological leadership in this field. However, given the currently high production costs, large-scale mass production of this model may be delayed until 2025.

The advantages of all-solid-state battery vehicles

1. Batteries are thinner and more compact, enabling greater power storage for vehicles.

Traditional lithium batteries are constrained by manufacturing processes—specifically, the separator and electrolyte together account for nearly 40% of the battery's volume and 25% of its mass.

However, all-solid-state batteries, thanks to their solid electrolyte, can reduce the distance between the positive and negative electrodes to just a few to over ten micrometers. This significantly decreases the battery's thickness, allowing far more all-solid-state cells to be packed into the same amount of space compared to conventional lithium-ion batteries. As a result, these batteries boast superior energy storage capacity and extended driving range.

On a larger scale, the advantages of thinness and small size also enable all-solid-state batteries to seamlessly integrate into a variety of innovative, compact smart electronic devices. (Once their thickness is reduced to below the millimeter level, these batteries can even be developed into flexible forms, making them bendable and foldable.) In this regard, traditional lithium-ion battery technology proves far less capable of achieving such advancements.

2. More Secure

Because traditional lithium batteries use liquid electrolytes, which are inherently flammable, explosive, and highly volatile, they can easily short circuit—and even catch fire—when subjected to external impacts or other extreme conditions, making it impossible to provide adequate safety protection.

However, all-solid-state batteries use solid electrolytes instead of liquid electrolytes, which are non-flammable, non-corrosive, and non-volatile—and they also eliminate the risk of leakage. Compared to conventional batteries, all-solid-state batteries inherently excel in thermal stability. Theoretically speaking, in terms of safety, all-solid-state battery-powered vehicles could outperform every existing lithium-ion battery vehicle on the market.

3. Batteries have higher energy density, enabling greater vehicle range.

Compared to the liquid lithium-ion batteries currently on the market, all-solid-state batteries not only offer superior safety but also boast a significantly higher energy density as their biggest highlight.

The key to achieving high energy density lies in eliminating the need for lithium-embedded graphite anodes altogether—instead, directly using metallic lithium as the anode material. This not only reduces the amount of anode material required but also significantly boosts the overall energy density of the battery. With a metallic lithium anode, the battery’s energy density could potentially reach 300–400 Wh/kg—or even higher—enabling compatibility with high-voltage cathode materials and further enhancing the gravimetric energy density. Such advancements, when applied to automotive applications, would dramatically improve vehicle range. Currently, many laboratories have already succeeded in small-scale, batch production of all-solid-state batteries boasting energy densities between 300 and 400 Wh/kg—far surpassing the typical 100–220 Wh/kg achieved by conventional lithium-ion batteries.

Additionally, many new high-performance electrode materials, which previously may not have been well compatible with existing electrolyte systems, can now see some improvement in compatibility when paired with all-solid-state electrolytes. Beyond these three major advantages, all-solid-state battery vehicles also offer: long battery cycle life, a wide operating temperature range, convenient battery recycling, rapid charging capabilities, and high production efficiency.

Solid-state batteries may be designated as a key technological project for tackling core challenges in new-energy vehicles.

Recently, an industry planning document labeled "New Energy Vehicle Industry Development Plan (2021-2035)" (Draft for Comments)—hereinafter referred to as the "Plan"—leaked online, sparking widespread excitement among many who believe it offers a sneak peek into the government's long-term vision for the new energy vehicle sector. According to the leaked version of the "Plan," specific targets have been set for the industrial development and technological innovation of both power batteries and fuel cells. Notably, "accelerating research and development and industrialization of all-solid-state power battery technology" has been designated by the leaked document as a "Key Core Technology Breakthrough Project" for the new energy vehicle industry. If these reports are accurate, the full-scale push to develop all-solid-state batteries could very well be elevated to the level of national strategic priority.

Overview of the Current Status of Solid-State Battery Companies

Ganfeng Lithium

Ganfeng Lithium has also chosen the oxide thick-film approach. According to its announcement, the company’s first-generation solid-state lithium battery prototype has successfully passed multiple third-party safety tests as well as sample evaluations conducted by several customers. The prototype boasts a single-cell capacity of 10 Ah and an energy density of at least 240 Wh/kg. After 1,000 charge-discharge cycles, the battery retains more than 90% of its original capacity, while the individual cell demonstrates a 5C-rate charge-and-discharge capability. As of December 31, 2018, Ganfeng’s 40 Ah solid-state lithium battery product had completed final design validation, with its safety metrics and overall performance meeting internal testing standards—already reaching the level of a fully developed prototype.

In March of this year, the pilot production line for the first-generation solid-state lithium batteries—capable of producing gigawatt-hour-scale annual output—began construction, with plans to complete and start operations in the second half of 2019.

Qingta New Energy

Qingtao is firmly committed to the solid-state polymer route. Last November, Qingtao completed its first production line capable of manufacturing solid-state batteries with a single-cell energy density reaching 400 Wh/kg, and launched its initial batch of solid-state lithium battery products, primarily targeting applications in specialized power sources, high-end consumer electronics, and other cutting-edge fields.

It has completed the construction of a pilot production line with an annual capacity of 100 MWh. Additionally, in July of this year, the signing ceremony for Qingtao New Energy's 10 GWh per year solid-state lithium-battery project was held in Yichun. The first phase of the project will have a solid-state battery production capacity of 1 GWh and is expected to begin operations by the end of this year. The second phase, with a capacity of 9 GWh, is scheduled to break ground by the end of June 2020 and will enter production within the following two years.

Beijing Weilan

Beijing Weilan is pursuing the oxide-plus-polymer solid electrolyte approach. They have developed a solid-state battery with a rated capacity of 4–8 Ah and an energy density of 240 Wh/kg. It’s reported that Beijing Weilan has already mastered several key technologies, including metallic lithium surface treatment, in-situ SEI film formation technology, solid electrolyte development, fast-ion-conducting material preparation techniques for lithium ions, as well as high-voltage battery integration technology, ceramic membrane optimization methods, and current collector solutions.

Currently, it is in the pilot-scale construction phase, with a total investment of 500 million yuan for the first-phase project. Production is set to begin in March 2020, and once completed, the facility is expected to achieve an annual production capacity of 100 MWh of solid-state batteries.

CATL

CATL primarily follows the sulfide-based approach. Currently, it has developed a polymer lithium-metal solid-state battery with a capacity of 325 mAh, achieving an energy density of up to 300 Wh/kg and maintaining over 82% of its initial capacity after more than 300 charge-discharge cycles.

BYD

BYD has not set any restrictions on its technological development roadmap for solid-state batteries, with both solid polymer and oxide types being its target areas. According to available information, the company has applied for an invention patent covering a cathode composite material for all-solid-state lithium-ion batteries, as well as an invention related to an all-solid-state lithium-ion battery itself.

Currently, its solid-state battery is in the small-scale trial phase. Meanwhile, according to foreign media reports, BYD's cutting-edge solid-state batteries will begin deliveries in Japan starting in 2021.

Jiawei

Jiawei is focusing on gel polymer technology. In July 2018, its 36Ah solid-state ternary soft-pack battery passed the national mandatory inspection. The energy density reaches 230Wh/kg, with a cycle life of 4,000 cycles, making it suitable for electric motorcycles—and priced at approximately 1.5 yuan/Wh.

Currently, it has completed the solid-state battery testing phase. Phase I, with a production capacity of 100 MWh (or equivalent to the pilot-line capacity), is already operational, while Phase II, which is currently under construction, will feature a capacity of 2 GWh.