What is a Deep-Cycle Battery?

To understand whether deep-cycle batteries can be used in cars, it’s important to first know what they are.

The term “deep cycle” refers to a key feature: the ability to undergo deep discharge. Unlike other batteries that discourage discharging beyond a certain range, deep-cycle batteries can be discharged to a large portion of their capacity.

Deep discharge means the battery is almost completely depleted of its charge. One full discharge and recharge is called a cycle. For example, if the battery is discharged to half its capacity and then recharged, that counts as one cycle. The deeper the discharge and recharge, the deeper the cycle, which is where the battery gets its name.

Deep-cycle batteries discharge slowly until fully depleted, then recharge for repeated use.

Key Features of Deep-Cycle Batteries

Deep-cycle batteries are designed for repetitive and deep discharge, making them ideal for applications requiring a stable power supply over long periods, such as golf carts, forklifts, and solar power systems.

• They provide longer operating times because they discharge slowly and continuously, often up to 80% of their capacity.
• They usually use lead-acid chemistry, but not all lead-acid batteries are deep-cycle. Many are marketed as marine batteries due to their use in boats.
• They have thicker plates, allowing them to withstand repeated discharge and recharge.
• Higher storage capacity enables a more stable power supply over extended periods.
• Although their lifespan is generally shorter than other types, their ability to endure frequent use makes them valuable in commercial and industrial applications.

Can Deep-Cycle Batteries Be Used in Cars?

While deep-cycle batteries can supply enough power to start a car, using them as a car battery is not recommended:

• Deep-cycle batteries continuously discharge and recharge, which can deplete and damage a car battery over time.
• Cars require a reserved charge to start reliably.
• Deep-cycle batteries are temperature-sensitive, posing risks in hot engine compartments.

In short, deep-cycle batteries are not suitable for regular automotive starting applications.

Applications of Deep-Cycle Batteries

Deep-cycle batteries are versatile and widely used in many fields:

1. Electric Boat Conversions: Provide reliable power for electric boats.
2. Industrial Electric Forklifts and Sweepers: Drive industrial equipment, improving efficiency.
3. Electric Wheelchairs: Ensure long-term power for mobility support.
4. Off-Grid Solar or Wind Storage Systems: Store electricity from renewable energy sources.
5. Small Devices for Remote Buildings or RVs: Power remote instruments or equipment.
6. Recreational Vehicles (RVs): Provide stable power for camper vans and motorhomes.
7. Traction Batteries: Power golf carts and other electric vehicles.
8. Traffic Signals: Maintain continuous operation for road safety.
9. Uninterruptible Power Supplies (UPS): Provide backup power for computers and equipment.
10. Sewage Pumps and Cathodic Protection: Support environmental engineering facilities.
11. Marine Applications: Power sailboats without onboard generation.
12. Trolling Motors for Fishing Boats: Enable recreational boating functions.
13. Audio Equipment: Deliver clean DC power for high-quality sound systems.

Overall, deep-cycle batteries play a critical role in clean energy and electrification, supporting a variety of applications that demand reliable power. The average lifespan is around 6 years, but careful maintenance and shallow discharge can extend this lifespan even further.

What is a Lithium Iron Phosphate (LiFePO4) Battery?

The lithium iron phosphate (LiFePO4) battery, also called the LiFePO4 lithium-ion battery, uses LiFePO4 as the positive electrode material and graphite as the negative electrode material. It has a single-cell rated voltage of 3.2V, with a charging cut-off voltage between 3.6V and 3.65V.

Among lithium batteries, LiFePO4 batteries are highly safe, environmentally friendly, long-lasting, and capable of high discharge rates, making them ideal for a wide range of applications.

Working Principle

Positive Electrode Material

Lithium Iron Phosphate (LiFePO4) serves as the positive electrode. Iron ions (Fe³⁺) are fixed within the crystal lattice. During charging, lithium ions (Li⁺) are extracted from the positive electrode and embedded into the negative electrode. During discharging, lithium ions return to the LiFePO4 structure.

Negative Electrode Material

Graphite is used as the negative electrode. Its structure can store and release lithium ions. During charging, lithium ions move from the positive electrode to the negative electrode through the electrolyte, embedding into the graphite. During discharging, the lithium ions leave the graphite and return to the positive electrode.

Electrolyte

The electrolyte, usually an organic solution or polymer film, allows lithium ions to move between electrodes during charge and discharge.

Separator

The separator prevents direct contact between positive and negative electrodes, avoiding short circuits.

Charging and Discharging Process

• Charging: An external voltage drives lithium ions from LiFePO4 through the electrolyte and separator, embedding into the graphite negative electrode for energy storage. Electrons flow through the external circuit to balance the ionic movement.
• Discharging: When connected to a load, lithium ions leave the graphite, move through the electrolyte and separator, and embed into the LiFePO4 positive electrode. Electrons flow back through the external circuit, delivering energy.

In detail, during charging, Li⁺ migrates from the (010) surface of LiFePO4 crystals, passes into the electrolyte under an electric field, traverses the separator, reaches graphene on the negative electrode, and embeds into the lattice. Electrons flow through the conductive materials to balance the charge.

During discharging, Li⁺ de-intercalates from graphite, travels through the separator to LiFePO4, while electrons move through the external circuit to the positive electrode.

Chemical Reactions

• Positive electrode: LiFePO4 → Li₁₋ₓFePO4 + xLi⁺ + xe⁻
• Negative electrode: xLi⁺ + xe⁻ + 6C → LixC6
• Overall reaction: LiFePO4 + 6xC → Li₁₋ₓFePO4 + LixC6

Key Advantages of LiFePO4 Batteries

• High working voltage and energy density
• Long cycle life
• Low self-discharge rate
• No memory effect
• Environmentally friendly
• Seamless scalability for large systems

Applications

LiFePO4 batteries are well-suited for large-scale energy storage, including:

• Renewable energy power stations
• Grid peak shaving
• Distributed power systems
• UPS power supplies
• Emergency power systems

These batteries show promising prospects due to their safety, long lifespan, and environmental benefits, making them a leading choice for modern energy storage solutions.

What is a 1.5V Lithium Battery?

A 1.5V lithium battery is a rechargeable lithium-ion battery that maintains a constant voltage of 1.5V throughout its entire discharge cycle without any drop. Internally, it uses a 3.6V lithium-ion cell, and through built-in circuitry, it regulates the output voltage to achieve 1.5V. This design provides strong power capabilities, making it ideal for devices that demand high current and voltage.

1.5V lithium batteries also support fast charging. For example, a single AA battery with a capacity of 3300mWh can fully charge in about 2 hours, whereas traditional nickel-metal hydride (NiMH) batteries may take around 10 hours.

Types of 1.5V Batteries

1. No. 1 Battery (D-type)

• Voltage: 1.5V
• Current: 1A
• Dimensions: Diameter 32.2mm, Height 59mm
• Short-circuit current: 1.5–2A

2. No. 5 Battery (AA-type)

• Most commonly disposable alkaline batteries
• Voltage: 1.5V
• Capacity: 600–700 mAh (for alkaline)
• Rechargeable variants include NiMH, NiCd (phased out), and iron lithium batteries
• NiMH: up to 2700mAh at 1.2V
• Iron lithium: up to 3000mAh at 3.2V

3. No. 7 Battery (AAA-type)

• Dimensions: Height 43.6 ±0.5mm, Diameter 10.1 ±0.2mm
• Types: dry cells, lithium batteries, NiMH, NiCd
• Common alkaline AAA batteries (e.g., LR03)
• Voltage: 1.5V, Capacity: ~1300mAh

Note: No. 5 batteries generally exceed 1600mAh, while No. 7 batteries usually do not exceed 900mAh.

Can 1.5V and 1.2V Batteries Be Interchanged?

It depends on the device. Devices with higher voltage requirements may not operate efficiently with 1.2V batteries. The key difference is that 1.2V batteries are rechargeable, while 1.5V batteries can be either rechargeable or disposable, depending on the type.

Advantages of 1.5V Lithium-Ion Batteries

Modern devices require reliable, rechargeable power sources. Disposable batteries are becoming less popular as many devices rely on electricity, making rechargeable lithium-ion batteries more practical and cost-effective.

Compared to NiMH batteries:

• Capacity does not fluctuate with charge state
• After repeated charging cycles, 1.5V lithium-ion batteries maintain about 80% capacity after 500–1000 cycles
• Reduce long-term operational costs

Before lithium-ion batteries, disposable alkaline batteries powered 1.5V devices. Lithium-ion batteries quickly replaced them due to rechargeability, eliminating the need for repeated battery replacements.

Environmental benefits:

• Reduce spent battery waste
• Minimize toxic materials such as mercury, lead, cadmium, and nickel in the environment
• Recyclable and more sustainable than disposable alternatives

Applications of 1.5V Lithium-Ion Batteries

1.5V lithium-ion batteries are widely used in daily life, powering:

• Small electronic devices (AA/AAA lithium-ion batteries)
• Household appliances
• Vehicles
• Hybrid and renewable energy storage systems

As the world shifts toward green energy from fossil fuels, 1.5V lithium-ion batteries will play an increasingly critical role. They are rechargeable up to 500–1000 times, which is roughly equivalent to 1000 disposable batteries, making them both economical and environmentally friendly.

Advancements in 1.5V Lithium-Ion Batteries

Ongoing research is improving the performance of 1.5V lithium batteries through new chemistries and designs, including:

• Lithium-sulfur
• Lithium-air
• Sodium-ion batteries
• Solid-state lithium batteries
• Lithium-ion solar batteries for higher energy density, lighter weight, and longer lifespan

These advancements allow 1.5V lithium-ion batteries to integrate with solar photovoltaics and other renewable energy technologies, further supporting sustainable energy solutions.

Since entering the market, lithium-ion batteries have gained widespread use thanks to their long lifespan, high specific capacity, and lack of memory effect. However, in low-temperature environments, they face significant challenges such as:

• Reduced capacity
• Severe degradation
• Poor cycling performance
• Pronounced lithium plating
• Unbalanced lithium stripping

With the expanding applications of lithium-ion batteries, these limitations in cold environments have become increasingly apparent.

At -20°C, the discharge capacity of lithium-ion batteries drops to about 31.5% of that at room temperature. While traditional lithium-ion batteries typically operate between -20°C and +55°C, industries like aerospace, defense, and electric vehicles require normal operation at -40°C. Thus, improving low-temperature performance is crucial.

Factors Constraining Low-Temperature Performance

Several factors limit lithium-ion batteries at low temperatures:

• Increased electrolyte viscosity or partial solidification, reducing conductivity
• Poor compatibility between the electrolyte, anode, and separator
• Severe lithium deposition on the anode, thickening the solid electrolyte interface (SEI)
• Hindered ion diffusion in active materials and increased charge-transfer impedance (Rct)

Electrolyte Impact on Low-Temperature Performance

The electrolyte has the most significant influence on cold-weather performance. Its composition and physicochemical properties determine:

• Ion conduction speed
• Electron migration matching
• Polarization effects during charge-discharge

At low temperatures, slow ion conduction can lead to lithium dendrite formation on the anode, causing battery failure. Higher electrical conductivity of the electrolyte ensures faster ion transport, improving capacity retention.

Key strategies to improve electrolyte performance include:

• Reducing solvent viscosity to maintain flowability at low temperatures
• Optimizing SEI film formation to lower impedance (RSEI)
• Using lithium salts with good dissociation properties to increase migrating ions

Notably, the main limitation in low-temperature performance is increased Li+ diffusion impedance, rather than the SEI film itself.

Low-Temperature Characteristics of Cathode Materials

Layered Cathode Materials

Layered cathodes, like LiCoO2, Li(Ni,Co,Mn)O2, offer stable 3D structures and fast 1D lithium diffusion channels. Tests show that at -30°C, LiCoO2/MCMB cells drop from 3.762V (0°C) to 3.207V, and total capacity decreases from 78.98 mAh to 68.55 mAh.

Spinel Cathode Materials

LiMn2O4 offers low cost and non-toxicity but suffers from structural instability due to the Jahn-Teller effect of Mn3+. The synthesis method affects electrochemical performance, with high-temperature solid-phase methods yielding higher charge transfer resistance (Rct) than sol-gel methods.

Phosphate Cathode Materials

LiFePO4 provides excellent safety and stability but poor low-temperature performance due to low electronic conductivity and lithium-ion diffusion. Its discharge voltage drops significantly at -20°C, but adding nano-carbon conductive agents improves low-temperature behavior. For example:

• Discharge voltage decreases only 9.12% from 25°C (3.40V) to -25°C (3.09V)
• Cell efficiency at -25°C improves to 57.3% from 53.4% without nano-carbon

LiMnPO4 is promising due to high voltage (4.1V) and large specific capacity (170 mAh/g), though lower ion conductivity often requires partial replacement with Fe to form LiMn0.8Fe0.2PO4.

Low-Temperature Characteristics of Anode Materials

Anode degradation is more severe due to:

• Severe polarization causing lithium metal deposition
• SEI film vulnerability under low-temperature effects
• Difficult lithium-ion diffusion in carbon anodes, leading to asymmetric charge-discharge

These factors contribute to significant low-temperature performance decline in anode materials.

Low-Temperature Electrolyte Research

The electrolyte plays a critical role in facilitating Li+ transfer. Key performance indicators include:

• Ion conductivity
• Electrochemical window
• Electrode reaction activity

EC-Based Electrolytes

Cyclic carbonates like ethylene carbonate (EC) have high dielectric constants and viscosity but provide strong ion conductivity and stable film formation, making them suitable for low-temperature use when mixed with low-melting-point solvents.

Lithium Salts

Lithium salt concentration affects ion conductivity, but the relationship is parabolic, depending on dissociation and complexation in the solvent.

Process and Operational Factors

• Electrode preparation: Lower loading and thinner coatings improve low-temperature capacity retention
• Charge-discharge state: Deep discharges can reduce cycle life and capacity
• Other factors: Electrode surface area, porosity, density, wettability, and separator quality affect low-temperature behavior

Key strategies include:

1. Forming a thin, dense SEI film
2. Ensuring high Li+ diffusion coefficients in active materials
3. Using high-conductivity electrolytes at low temperatures

Future Outlook: Solid-State Lithium-Ion Batteries

Solid-state lithium-ion batteries, especially thin-film types, show potential to overcome capacity decay and cycling issues in low temperatures, offering a promising alternative to conventional lithium-ion batteries.

As is well known, for a long period, around 90% of the global lithium battery market was dominated by foreign companies, particularly those from Japan and South Korea. However, today, China has taken a leading position in multiple core supply chains of the global lithium battery industry.

For example:

• China’s EV battery shipments account for roughly 56.9% of the global total.
• Energy storage battery shipments hold an 87% global share.
• Shipments of positive/negative electrode materials make up about 90% of the market.
• Electrolyte shipments contribute over 85%, and lithium-ion battery separators occupy over 80% globally.

Entrepreneurs Fueling the Industry

In this dynamic era, numerous entrepreneurs have emerged in the lithium battery sector, enduring ups and downs, driven by a spirit of determination and the pursuit of victory. Some have pursued research with the dedication of ascetic monks. Their collective efforts have helped establish the remarkable rise of China’s lithium battery industry, now capturing worldwide attention.

Clausewitz once said in On War: “Great generals light up their hearts in the vast darkness, illuminating the way forward with a faint light.”

Today, the lithium battery industry is entering a new phase of competition and reshuffling. Some analysts even warn that the industry is facing “super capacity surplus”, predicting intensifying competition and a potentially ruthless market elimination process. In recent months, industry leaders have warned about risks associated with overcapacity and extreme price wars in the EV and energy storage sectors.

The Human Factor in Industry Success

The rise or fall of a company often comes down to human factors. Leadership decisions heavily influence overall success and can even shape the industry’s future direction. Data from 2023 show that, despite fierce competition, many companies still maintain double-digit revenue growth, strengthen capital strength, expand international strategies, and continue technological breakthroughs and industrialization. This demonstrates the enduring spirit and resilience of entrepreneurs.

A Brief History of Lithium Batteries

The development of the lithium battery industry began in the late 20th century. After European, American, Japanese, and South Korean countries competed for dominance, competition became increasingly fierce. Within just a decade, China achieved qualitative breakthroughs, rising to a global leadership position.

• In 2019, Yoshino Akira of Japan won the Nobel Prize in Chemistry, recognizing decades of research since 1981, including the invention of a rechargeable battery with a polyacetylene anode and a lithium cobalt oxide cathode in 1983.
• In 1991, Sony introduced the world’s first lithium-ion battery with a cylindrical design, a lithium cobalt oxide cathode, and a carbon anode, which powered their camcorder products.
• Japan initially dominated the market, with Panasonic, Toshiba, and Sanyo leading research. By around 2000, Japan produced 90% of global lithium batteries.

However, many Japanese companies shifted focus to hydrogen fuel cell research, and the country’s lithium battery sector stagnated. South Korea quickly seized the opportunity, with companies like Samsung SDI and LG advancing rapidly, supported by government initiatives, and capturing significant market share.

By 2010, Japan and South Korea were major players, holding roughly 50% and 30% of the global market, respectively, while China was just beginning its lithium battery production and research.

China’s Strategic Rise

China entered the lithium battery sector relatively late. While Japanese lithium batteries were entering 3C products in 1992, China completed its first lithium-ion battery production line in 1997. Early on, many Chinese companies were skeptical about the future of lithium batteries. However, thanks to scholars like Chen Liquan, the “Father of China’s Lithium Batteries”, the technology gained traction.

Over the years, continuous breakthroughs have enabled China to scale production and diversify applications—from mobile phones and computers to electric vehicles, a rapidly growing frontier.

China’s advantages include:

• Control of roughly half of the world’s lithium ore resources.
• Dominance in lithium battery production, representing around 80% of global output.
• Strategic early entry into the European EV market, leveraging domestic policies, subsidies, and a growing consumer base.

These factors have propelled Chinese lithium batteries to a global leadership position in technology, market share, and supply chain management.

Challenges Ahead

Despite its success, China’s lithium battery industry still faces challenges:

• Battery standardization: Crucial for long-term industry sustainability.
• Overcapacity: Needs careful management to maintain stable growth.

China’s journey demonstrates that with strategic planning, technological innovation, and resilient leadership, the nation has transformed from a late entrant to a dominant force in the global lithium battery market.

In the field of energy storage, a new frontier is emerging that could transform how we think about energy: quantum batteries. Rooted in quantum mechanics, this revolutionary concept has achieved remarkable progress in laboratory settings, including recent breakthroughs in Indefinite Causal Order (ICO) charging. Yet, turning these laboratory achievements into practical, everyday technology remains a complex and challenging journey.

The Innovative Frontier of Quantum Batteries

Quantum batteries are more than just an improvement on traditional batteries—they represent a fundamental shift in energy storage. Unlike conventional batteries, which rely on chemical reactions to store energy, quantum batteries utilize the quantum states of particles, including phenomena such as superposition and entanglement. These unique properties could enable faster charging and higher energy efficiency.

Energy in quantum batteries is stored in the excited states of quantum particles. When particles return to their ground state, the battery discharges; charging occurs when particles are in the excited state.

The theoretical potential for ultra-fast charging arises from quantum superposition, allowing multiple particles to charge simultaneously as a single entity, significantly speeding up the charging process.

One major advancement in this area is the Indefinite Causal Order charging research, a collaboration between the University of Tokyo and the Beijing Computational Science Research Center. This approach challenges traditional concepts of time and causality, enabling a charging process without a fixed sequence of events in the quantum realm. In other words, causality can blur at the quantum level, leading to more efficient energy storage and transmission.

Experimental studies, particularly those using photon quantum switches, show that this method can improve both charging capacity and thermal efficiency. Interestingly, the research also suggests that lower-power chargers may charge quantum batteries more efficiently than higher-power ones, a counterintuitive finding.

Future Prospects and Applications

The potential of quantum batteries extends far beyond faster smartphone charging or more efficient laptops. They could transform renewable energy systems, electric vehicles, and large-scale grid storage. Their ability to charge rapidly and efficiently could make solar and wind power systems more effective, reducing reliance on fossil fuels and helping combat climate change.

The Long Road to Practical Applications

Despite the promising lab results, several hurdles remain before quantum batteries become commercially viable:

• Quantum coherence: Quantum states are fragile and easily disrupted by the environment—a phenomenon called decoherence. Maintaining stable quantum states under everyday conditions is a major challenge.
• Scalability: Currently, quantum batteries exist mostly as small-scale lab experiments. Scaling up for consumer or industrial use presents significant engineering and manufacturing challenges.
• System integration: Quantum batteries operate under quantum principles, which differ from classical physics that govern existing technology. Bridging this gap to integrate quantum and classical systems efficiently is essential for practical deployment.

In conclusion, quantum batteries exemplify human innovation and our drive to push technological boundaries. Breakthroughs like Indefinite Causal Order charging are important steps forward, yet the path to widespread use remains long and filled with challenges. As research in quantum mechanics continues, the dream of quantum batteries powering our future remains a bright but distant beacon on the horizon of energy technology.

By 2030, global shipments of solid-state batteries are expected to surpass 614.1 gigawatt-hours (GWh), with a market size exceeding 250 billion yuan. The penetration rate of solid-state batteries in the overall lithium battery market is projected to reach around 10%, mainly driven by the adoption of semi-solid-state batteries.

The China Battery Industry Research Institute released the White Paper on the Development of China’s Solid-State Battery Industry (2024), defining batteries with less than 10% liquid electrolyte as semi-solid-state batteries and those completely devoid of liquid electrolyte as full solid-state batteries. As the liquid electrolyte content decreases and the solid electrolyte content rises, batteries are expected to show higher energy density and improved safety performance.

Industrialization Progress

Since 2022, significant strides have been made in the research and industrialization of solid-state batteries, especially in China. Chinese companies have achieved mass production and installation of semi-solid-state batteries, marking the economic industrialization of semi-solid-state batteries in 2023.

In contrast, full solid-state batteries still face technical challenges, including ion conductivity issues, solid-solid interface problems, and limited cycle performance. The industrialization of full solid-state batteries is anticipated to occur around 2030.

Market Forecast and Drivers

Based on current technology assessments and cost reduction paths, global shipments of solid-state batteries are expected to reach 614.1 GWh by 2030, with a market share of approximately 10% in the overall lithium battery industry. The total market size is projected to exceed 250 billion yuan, with semi-solid-state batteries acting as the main driver of growth.

The substantial increase in projected shipments is largely attributed to the remarkable R&D progress and cost reductions achieved by Chinese companies in semi-solid-state battery technology.

Competitive Landscape

Overseas companies, particularly from Japan and the United States, have been early adopters of solid-state battery research, primarily targeting full solid-state batteries. However, their industrialization progress has been relatively slow.

In contrast, Chinese companies have taken a more pragmatic approach by developing semi-solid-state batteries as transitional products, enabling faster industrial development and helping the domestic industry gain a competitive edge in both technology and market adoption.

The combination of industrialized semi-solid-state batteries and ongoing R&D toward full solid-state batteries positions China as a leader in the global solid-state battery landscape, with significant implications for energy storage, electric vehicles, and next-generation lithium-ion applications.

Lithium Replenishment Technology: Enhancing Energy Density and Cycle Life in Lithium-Ion Batteries

In recent years, the rapid growth of new energy vehicles has raised the bar for lithium-ion battery performance. Among all requirements, improving energy density has become the most urgent.

Currently, there are two main approaches to boost energy density:

1. Structural optimization – through technologies like CTP (cell-to-pack), CTC (cell-to-chassis), and CTB (cell-to-body).
2. Material iteration – using advanced electrode materials, such as high-nickel ternary cathodes, high-voltage nickel-manganese materials, and high-capacity silicon or tin-based alloy anodes.

Another important method is lithium replenishment technology, also known as pre-lithiation, which directly addresses lithium loss during initial cycling.

Why Lithium Replenishment Matters

When a lithium-ion battery is first charged, the electrolyte decomposes on the anode surface (e.g., graphite), forming a Solid Electrolyte Interface (SEI). While necessary, this consumes a significant amount of lithium, lowering the initial cycle efficiency (ICE) and reducing overall capacity and energy density.

Further lithium loss occurs due to inactive anode particles and irreversible lithium deposition. Over time, these factors degrade performance.

Lithium replenishment technology solves this by pre-loading lithium into the battery before operation. By compensating for lithium losses, it improves ICE, extends cycle life, and enhances energy density.

For graphite anodes, irreversible capacity loss exceeds 6%. For high-capacity silicon and tin-alloy anodes, it can reach 10–30%. Pre-lithiation offsets these losses, unlocking their full potential.

Two Approaches to Lithium Replenishment

Lithium replenishment falls into two categories:

• Negative electrode replenishment
• Positive electrode replenishment

I. Negative Electrode Replenishment

This method introduces active lithium into the anode. Common approaches include:

1. Physical Mixing

Researchers have directly pressed lithium foil onto graphite or silicon anodes to restore lithium. For example, in 2019, Tongji University developed a roll-to-roll pre-lithiation process using Sn and lithium foils. The resulting LixSn material proved stable in air and retained 90% capacity after humidity exposure, making it suitable for LFP|Sn cells.

2. Vacuum Winding Plating

By using vacuum coating in roll-to-roll operations, large-scale uniform lithiation can be achieved. However, commercialization is still limited by cost and safety.

3. Chemical Lithiation

This involves reactions between lithium-rich agents (e.g., lithium powder, LiOH, molten lithium, or Li-organic composites) and the anode. FMC’s Stabilized Lithium Metal Powder (SLMP) is a leading example, applied through spraying or slurry coating.

4. Self-Discharge Mechanism

Here, lithium foil contacts the anode in an electrolyte environment, triggering spontaneous lithium insertion. This method is useful for studying morphology-performance relationships.

5. Electrochemical Lithiation

Widely used in research, this method introduces metallic lithium with the anode and controls lithiation through electrochemical cycling. Huawei and Tesla hold patents in this area, while Xiaomi has already commercialized high-silicon pre-lithiation in mobile phone batteries.

II. Positive Electrode Replenishment

Compared to the anode approach, cathode pre-lithiation is simpler, safer, and cheaper. Lithium-rich additives can be blended into the cathode slurry without altering existing manufacturing processes.

Requirements for Effective Cathode Replenishment:

1. The additive’s delithiation potential must fit within the cathode’s operating voltage range.
2. It should have high specific and volumetric capacity (>350 mAh/g).
3. It must be chemically stable with current binders, solvents, and electrolytes.
4. It should remain stable in air or dry environments.

Key Materials

• Binary lithium compounds: Li2O, Li2O2, Li3N, Li2S
  • Example: Guoxuan High-Tech’s rGO@Li2O/Co nanocomposites improved conductivity and stability.
  • Tesla’s patents include Li2O, Li2O2, and Li3N as sacrificial additives.
• Lithium-rich compounds: Li5FeO4, Li2NiO2
  • Li5FeO4 offers high capacity but requires better air stability.
  • Li2NiO2 can improve ICE but struggles with stability and impedance.
• Lithium composites: Li2S/Co, LiF/Co, Li2O/Co
  • These materials combine high capacity with improved conductivity and stability, though residues can remain after cycling.

Industrialization Challenges and Outlook

Negative electrode pre-lithiation, despite being well-studied, faces safety risks with metallic lithium and remains difficult to commercialize at scale. Positive electrode pre-lithiation offers better safety and process compatibility, but material challenges remain.

Future research must focus on:

• Stable, safe pre-lithiation agents with low decomposition potential
• Materials that don’t generate gas or harmful byproducts
• Compatibility with mainstream battery manufacturing

Conclusion

Lithium replenishment technology is emerging as a key enabler for next-generation lithium-ion batteries, improving both energy density and cycle life. While challenges remain—particularly in material stability and manufacturing—ongoing research and patents from major players like Tesla, Huawei, CATL, and Xiaomi indicate strong momentum toward commercialization.

As the energy transition accelerates, lithium replenishment could become a cornerstone technology for advancing electric vehicles, consumer electronics, and energy storage systems.

Why Chinese Battery Companies Are Going Global

Since 2023, the export of power batteries has become a hot topic. For leading Chinese manufacturers, stepping into the global market is not just an option—it’s a necessity. Expanding overseas helps relieve domestic overcapacity, capture larger market share, and navigate growing trade barriers.

But going global isn’t easy. Companies face three major hurdles:

1. Building benchmark factories abroad.
2. Validating localized products that meet regional standards.
3. Achieving long-term profitability for overseas operations.

Global New Energy Vehicle Growth

Between January and September 2023, global sales of new energy vehicles (NEVs) reached 9.4 million units, a 39% increase year-on-year, representing about 16% of global car sales.

China remained the clear leader, selling 5.92 million units—up 36% year-on-year—with a domestic market share of 29.8%. In fact, China accounted for more than 60% of global NEV sales.

Looking ahead, China will remain a core market, but growth momentum is shifting. The U.S. and Europe are emerging as high-potential regions, growing faster than China in relative terms. Meanwhile, Southeast Asia, the Middle East, and even Pacific markets like the U.S. provide new frontiers for expansion.

Challenges of Internationalization

Going global means navigating not just logistics but also cultural, regulatory, and operational differences.

• Cultural differences: Chinese companies tend to be more reserved, while Western business culture emphasizes open communication.
• Regulatory differences: Europe, for example, has slower and more complex approval processes.
• Behavioral differences: China’s business style is flexible and fast-moving, whereas Europe emphasizes strict standardization and step-by-step execution.

For success, Chinese battery firms must:

1. Stay legal and compliant in each market.
2. Respect local business and cultural practices.
3. Build collaborative supply chains.

At the core, effective communication and resilience in the face of uncertainty will define who thrives abroad.

Branding and Long-Term Strategy

Although only a fraction of Chinese companies are currently capable of large-scale globalization, individual efforts contribute to shaping a strong Chinese brand image worldwide.

Future success requires a long-term mindset, with:

• Technology as the driving force
• Products as the foundation
• Quality as the essence
• Compliance as the baseline

The Current Market Cycle

The lithium battery sector was booming in 2021 and 2022, but 2023 brought challenges. Despite overall oversupply, demand for plug-in hybrid and hybrid vehicle batteries remained tight.

Looking ahead:

• Q1 2024 is expected to stay difficult, with continued pressure on the industry.
• By the second quarter of 2024, however, political and economic headwinds may ease as countries turn toward economic recovery, supporting a rebound.

Industry experts see the current large-scale adjustment not as a crisis, but as a natural cooling-off period after years of rapid growth. This reset is essential to prepare for the next expansion phase.

Outlook Beyond 2025

Starting in 2025, new energy consumption will move from being driven primarily by early adopters to becoming mainstream among ordinary consumers. At that point, global demand for NEVs and batteries will accelerate on a much larger scale.

For Chinese power battery companies—whether competing at home or overseas—success will rest on delivering reliable, high-quality products backed by strong manufacturing capabilities.