I examine the patent landscape for thermal control of the electric vehicle battery pack from 2007 through 2025. In my view, the electric vehicle battery pack is not simply an energy storage container; it is a coupled electrochemical, thermal, electrical, and mechanical system. Its usable range, power delivery, cycle life, fast-charging capability, and safety all depend on keeping the electric vehicle battery pack within a narrow operating window. The reviewed patent data show that thermal control has moved from a secondary cooling function to a central design discipline for the electric vehicle battery pack.
I begin with the physical target that dominates the entire patent field. For a lithium-ion electric vehicle battery pack, the preferred operating range is approximately 15 to 35 degrees Celsius, and the maximum temperature difference among cells should remain within 5 degrees Celsius. These two conditions can be written as:
$$T_{\text{target}} = \{T \mid 15^\circ\mathrm{C} \le T \le 35^\circ\mathrm{C}\}$$
$$\Delta T_{\text{cell}} = \max_{i,j}|T_i – T_j| \le 5^\circ\mathrm{C}$$
I also use the lumped thermal balance of the electric vehicle battery pack as a reference equation for interpreting patent activity:
$$C_{\text{th}} \frac{dT_{\text{pack}}}{dt} = Q_{\text{gen}} – Q_{\text{diss}}$$
Here, \(Q_{\text{gen}}\) is the heat generated by the electric vehicle battery pack, \(Q_{\text{diss}}\) is the heat removed by the thermal management system, and \(C_{\text{th}}\) is the effective thermal capacitance of the electric vehicle battery pack. The heat generation term can be approximated as:
$$Q_{\text{gen}} = I^2 R_{\text{int}} + I T \frac{\partial U}{\partial T}$$
The heat removal term depends on the cooling route. For a liquid-cooled electric vehicle battery pack, I write:
$$Q_{\text{diss}} = \dot{m} c_p (T_{\text{out}} – T_{\text{in}})$$
For a phase-change material, the thermal buffer is:
$$Q_{\text{PCM}} = m L_f + m c_p \Delta T$$
These equations frame my patent analysis. When I see a cluster of patents around flow channels, coolant plates, refrigerants, or phase-change composites, I interpret it as an attempt to increase \(Q_{\text{diss}}\), reduce \(\Delta T_{\text{cell}}\), or decouple the electric vehicle battery pack from harsh ambient conditions.
My patent-data lens
I use patent applications and grants as the main signals. I do not treat every patent as an equally valuable invention. Instead, I read the electric vehicle battery pack thermal control field through count, growth, geographic origin, applicant concentration, and technology route. Table 1 summarizes the metrics I apply.
| Metric | Formula | What I infer |
|---|---|---|
| Annual application count | $$P_t$$ | Short-term inventive activity |
| Annual grant count | $$G_t$$ | Maturity and examination outcomes |
| Growth rate | $$g_t = \frac{P_t – P_{t-1}}{P_{t-1}}$$ | Speed of entry into the field |
| Compound annual growth rate | $$CAGR = \left(\frac{P_t}{P_0}\right)^{1/(t-t_0)} – 1$$ | Long-run expansion |
| Geographic share | $$s_i = \frac{P_i}{\sum_j P_j}$$ | Innovation origin concentration |
| Concentration ratio | $$CR_n = \sum_{i=1}^{n} s_i$$ | Dominance of leading applicants |
| Herfindahl-Hirschman index | $$HHI = \sum_{i=1}^{n} s_i^2$$ | Portfolio concentration |
| Cell temperature spread | $$\Delta T = T_{\max} – T_{\min}$$ | Uniformity of the electric vehicle battery pack |
| Cooling power | $$\dot{Q} = \dot{m} c_p \Delta T$$ | Heat removal capacity |
| Thermal resistance | $$R_{\text{th}} = \frac{\Delta T}{\dot{Q}}$$ | Resistance to heat flow |
| Phase-change latent heat | $$Q_{\text{PCM}} = m L_f$$ | Passive thermal buffer |
| Temperature uniformity index | $$\sigma_T = \sqrt{\frac{1}{N}\sum_{i=1}^{N}(T_i-\bar{T})^2}$$ | Spatial quality of thermal control |
My first conclusion is that the electric vehicle battery pack thermal control field has a very clear life cycle. It begins with low-volume experimentation, accelerates when lithium-ion batteries become dominant, stabilizes around high patent counts, and then enters a period of selective quality improvement. I describe this as a four-stage evolution: sprouting, explosion, high-level fluctuation, and rational adjustment.
Four-stage patent evolution
From 2007 to 2014, I find a low base and slow growth. The average annual application count is about 38. During this period, the electric vehicle battery pack was often based on lead-acid or nickel-metal hydride chemistry in pilot and hybrid applications. The thermal load was lower, and basic air cooling was often sufficient. The electric vehicle battery pack did not yet require the sophisticated liquid-cooling architectures that dominate later years.
From 2015 to 2018, I see explosive growth. Applications rise from 142 in 2015 to 759 in 2018. The four-year increase is about 434.5 percent. The compound annual growth rate is above 60 percent, and my own calculation from the endpoint values gives:
$$CAGR_{2015-2018} = \left(\frac{759}{142}\right)^{1/3} – 1 \approx 0.748 = 74.8\%$$
This is a period in which the electric vehicle battery pack shifts toward lithium-ion chemistry, pure electric platforms expand, and thermal control becomes a bottleneck. Air cooling begins to lose its position as the default solution. Liquid-cooling plates, coolant circulation loops, and pack-level thermal architectures become the center of patent activity for the electric vehicle battery pack.
From 2019 to 2024, I observe high-level fluctuation and steady optimization. The average annual application count is about 733. The trend is not a simple straight line; it fluctuates upward and reaches a peak in 2024. In my reading, this is the stage where the electric vehicle battery pack thermal control field shifts from basic invention to engineering refinement. Patents focus on flow uniformity, compactness, integration with vehicle thermal systems, and cost reduction.
In 2025, I see a rational adjustment. The application count is 684, about 25.3 percent lower than the previous year. However, this is still above the pre-2021 level. I estimate the 2024 value as:
$$P_{2024} \approx \frac{684}{1-0.253} \approx 916$$
The decline does not mean that the electric vehicle battery pack has become less important. Rather, I interpret it as a combination of standardization, fewer basic improvements, and the fact that some applications are not yet published. The electric vehicle battery pack thermal control field is becoming more selective.
| Stage | Years | Application pattern | Main driver I identify | Dominant thermal route for the electric vehicle battery pack |
|---|---|---|---|---|
| Sprouting | 2007-2014 | Average about 38 per year | Pilot electric vehicles and hybrid platforms | Basic air cooling |
| Explosion | 2015-2018 | 142 to 759; 434.5 percent total growth | Lithium-ion adoption and policy support | Liquid cooling begins to replace air cooling |
| High-level fluctuation | 2019-2024 | Average about 733; 2024 peak | Large-scale market and system optimization | Liquid cooling becomes mainstream |
| Rational adjustment | 2025 | 684; about 25.3 percent annual decline | Standardization and quality focus | Composite and intelligent thermal control |
The grant trend reinforces this interpretation. From 2015 to 2017, I see continuous high-speed growth in grants. In 2018, grants reach a peak. This peak marks a transition from quantity accumulation to quality improvement. From 2019 to 2024, grants remain at a high level and enter a stable phase. For the electric vehicle battery pack, this means that many core concepts have already been protected, and later patents must compete on integration, control precision, and manufacturing feasibility.
| Grant phase | Years | My interpretation |
|---|---|---|
| High-speed grant growth | 2015-2017 | Core window for electric vehicle battery pack thermal breakthroughs |
| Grant peak | 2018 | Shift from volume to quality |
| Stable high-level grants | 2019-2024 | Mature engineering and integration phase |
Geographic origin of patent activity
When I group applications by origin, I find an extremely concentrated pattern. China accounts for about 6,930 applications, or 96.3 percent of the global total. Japan is second with about 157 applications, or 2.2 percent. The United States has about 46 applications, South Korea about 41, and Germany about 10. France, the United Kingdom, Canada, and Singapore each have fewer than 10 applications. I estimate the global total as:
$$N_{\text{total}} \approx \frac{6930}{0.963} \approx 7196$$
The ratio between the leading origin and the second origin is striking:
$$\frac{s_{\text{China}}}{s_{\text{Japan}}} \approx \frac{96.3}{2.2} \approx 43.8$$
In my view, this geographic concentration is not accidental. It reflects four reinforcing forces. First, policy guidance has made the electric vehicle battery pack a strategic industrial target. Second, large-scale market demand creates a feedback loop from deployment to research and patent filing. Third, a complete supply chain from materials to cells to system integration supports rapid iteration. Fourth, patent awareness has risen sharply among firms working on the electric vehicle battery pack.
| Origin | Applications | Share | Relative to the leading origin |
|---|---|---|---|
| China | 6,930 | 96.30% | 1.00 |
| Japan | 157 | 2.18% | 0.023 |
| United States | 46 | 0.64% | 0.0066 |
| South Korea | 41 | 0.57% | 0.0059 |
| Germany | 10 | 0.14% | 0.0014 |
| Other four origins combined | About 12 | About 0.17% | About 0.0017 |
I do not read this as a lack of innovation elsewhere. Instead, I read it as a difference in commercialization focus. The electric vehicle battery pack is manufactured, assembled, and integrated at massive scale in China, so patent filings follow production, testing, and supply-chain learning. However, because thermal control is safety-critical, I expect cross-border patent activity to remain important for high-value markets.
Applicant concentration and industrial structure
The applicant landscape for the electric vehicle battery pack thermal control field is highly concentrated. I anonymize the leading entities because my focus is on structure rather than individual names. The top three applicants together hold about 657 applications, or 57.7 percent of the top-applicant total. The top five hold about 74.8 percent. This is an oligopolistic pattern. The leading applicant alone has about 342 applications, or 30.1 percent of the top-applicant total. The second applicant has about 217 applications. The ratio between the first and second is about 1.6.
$$\frac{P_1}{P_2} = \frac{342}{217} \approx 1.58$$
I calculate the concentration ratios as:
$$CR_3 \approx 0.577$$
$$CR_5 \approx 0.748$$
I also estimate the Herfindahl-Hirschman index for the leading group. Using the top five shares and the remaining share, I obtain:
$$HHI \approx 0.3005^2 + 0.1907^2 + 0.0861^2 + 0.0861^2 + 0.0844^2 + 0.2522^2 \approx 0.212$$
This value indicates a concentrated innovation structure. In my interpretation, the electric vehicle battery pack thermal control field is not a fragmented landscape of small inventors. It is shaped by large manufacturers, vehicle integrators, and a smaller number of research universities that supply foundational work.
| Rank | Entity type | Applications | Share of top-applicant total |
|---|---|---|---|
| 1 | Battery manufacturer | 342 | 30.1% |
| 2 | Vehicle and battery integrator | 217 | 19.1% |
| 3 | Vehicle group | 98 | 8.6% |
| 4 | University | 98 | 8.6% |
| 5 | Traditional automaker | 96 | 8.4% |
| Top 3 total | Mixed industrial entities | 657 | 57.7% |
| Top 5 total | Mixed industrial and university entities | About 851 | 74.8% |
From the perspective of institution type, I find that enterprises are the absolute innovation subject. Seven enterprises together account for about 906 applications, or 79.6 percent of the top-ten total. Their average application count is about 129. Three universities together account for about 20.4 percent, with an average of about 77 applications. One university even exceeds a traditional automaker in application count. This tells me that the electric vehicle battery pack thermal control field relies on a division of labor: firms drive application-oriented development, while universities provide materials, algorithms, and fundamental thermal science.
| Institution type | Number of entities | Applications | Share | Average per entity |
|---|---|---|---|---|
| Enterprises | 7 | 906 | 79.6% | 129 |
| Universities | 3 | 232 | 20.4% | 77 |
I also observe full supply-chain coverage. Battery makers, vehicle-and-battery integrators, vehicle groups, new-energy vehicle makers, traditional automakers, and even appliance or thermal-management entrants all file patents related to the electric vehicle battery pack. This diversity suggests that thermal control is a boundary-spanning technology. It connects electrochemistry, fluid mechanics, control theory, materials science, and vehicle architecture.
Technology route analysis
The reviewed patents cluster around four main routes: air cooling, liquid cooling, refrigerant direct cooling, and phase-change material thermal control. I treat these as the backbone of the electric vehicle battery pack thermal control field. Each route has a different physical mechanism, patent maturity, and application fit. I compare them in Table 6.
| Route | Mechanism | Core components | Strengths | Limitations | My maturity judgment |
|---|---|---|---|---|---|
| Air cooling | Forced or natural air convection | Air ducts, inlet and outlet ports, sensors, controller | Simple, low cost, easy maintenance | Low heat transfer coefficient, uneven temperature | Mature but limited for high-energy electric vehicle battery pack |
| Liquid cooling | Single-phase coolant circulation | Cold plates, pump, chiller, valves, sensors, controller | High heat removal, good uniformity | Complex sealing, mass, pump energy | Current mainstream for electric vehicle battery pack |
| Refrigerant direct cooling | Refrigerant evaporation inside battery channels | Compressor, condenser, expansion valve, direct cooling plate | Fast cooling, high latent heat, compact integration | Control complexity, refrigerant distribution, cost | High-end and advancing route |
| Phase-change material | Latent heat absorption and release | PCM composites, heat spreaders, optional liquid loop | Passive uniformity, low parasitic energy | Thermal conductivity, volume change, cycling stability | Promising for composite electric vehicle battery pack systems |
Air cooling patents
Air cooling is the earliest and simplest route for the electric vehicle battery pack. It uses air as the cooling medium. The heat removal equation is:
$$Q_{\text{air}} = \dot{m}_{\text{air}} c_{p,\text{air}} \Delta T_{\text{air}}$$
Because air has a relatively low density and low specific heat, the achievable heat transfer coefficient is limited. Early patents therefore focused on flow-path design, fan control, and temperature sensing. I see many inventions that try to improve the electric vehicle battery pack by switching airflow direction. In one generic scheme from my data set, a ring-shaped duct and a damper mechanism create two switchable cooling paths. The controller monitors the highest cell temperature and the temperature difference between the two ends of the pack. When the difference rises, the airflow direction reverses. This alternating flow can reduce the internal temperature difference by about half while still cooling the hottest region.
In my assessment, air cooling remains relevant for low-power or cost-sensitive electric vehicle battery pack applications. However, it is not sufficient for high-energy-density packs under fast charging. The core limitation is not the fan; it is the low thermal capacity of air and the difficulty of delivering uniform flow to every module.
Liquid cooling patents
Liquid cooling is the dominant industrial route for the electric vehicle battery pack. A typical system includes a cold plate, pump, chiller, multi-way valve, temperature sensors, and a controller. The heat transfer is much stronger because the coolant has higher density and specific heat than air:
$$Q_{\text{liquid}} = \dot{m}_{\text{liquid}} c_{p,\text{liquid}} (T_{\text{out}} – T_{\text{in}})$$
The thermal resistance of the cold plate can be expressed as:
$$R_{\text{th}} = \frac{1}{h A}$$
Patents in this area focus on channel geometry, flow distribution, sealing, compactness, and integration with the vehicle cabin or powertrain thermal loop. I see many designs that combine liquid cooling with conduction and air cooling. In one generic architecture, a battery array is interspersed with multiple cooling plates, a water loop provides primary heat removal, heat is conducted through plates and tubes to finned external surfaces, and when the temperature exceeds a threshold, an air pump and fan introduce filtered air for enhanced convection. The system also has automatically openable heat-dissipation holes that balance cooling and sealing.
I interpret liquid cooling as the reference design for the electric vehicle battery pack. Its patent density is high because it must satisfy multiple constraints at once: cooling capacity, temperature uniformity, leakage safety, mass, volume, and energy consumption. The future patent space is therefore less about the basic idea of a cold plate and more about adaptive flow control, low-pressure-drop channels, and integration with heat pumps.
Refrigerant direct cooling patents
Refrigerant direct cooling takes a different path. Instead of cooling a secondary liquid, it sends refrigerant directly into channels adjacent to or inside the electric vehicle battery pack. The refrigerant evaporates and absorbs latent heat:
$$Q_{\text{evap}} = \dot{m}_{\text{ref}} (h_{\text{out}} – h_{\text{in}})$$
The cooling coefficient of performance can be defined as:
$$COP = \frac{Q_{\text{cooling}}}{W_{\text{compressor}}}$$
I find patents that integrate cooling and heating modes. A four-way reversing valve can switch refrigerant flow, a dual expansion branch can feed different heat exchangers, and a liquid-liquid heat exchanger can cool or heat a secondary coolant. In high-temperature conditions, the refrigerant loop cools the electric vehicle battery pack. In low-temperature conditions, a heat pump mode can preheat the electric vehicle battery pack. Sensors and a controller coordinate the compressor, expansion valves, pump, and solenoid valves over a vehicle network.
This route is attractive because it can achieve fast cooling and compact packaging. However, I also see challenges. Refrigerant distribution among many parallel channels is difficult. The electric vehicle battery pack may experience maldistribution, local dry-out, or excessive pressure drop. Control is also more complex because the battery thermal loop and the cabin air-conditioning loop interact. For these reasons, I classify refrigerant direct cooling as an advanced route with high patent value but narrower manufacturing maturity than liquid cooling.
Phase-change material patents
Phase-change material thermal control uses the latent heat of a solid-liquid transition to buffer the electric vehicle battery pack. The basic energy relation is:
$$Q_{\text{PCM}} = m L_f + m c_p \Delta T$$
When the electric vehicle battery pack generates heat, the PCM melts and absorbs energy. When the pack cools, the PCM solidifies and releases energy. This provides passive temperature uniformity without a pump or fan. The main technical barriers are low thermal conductivity, volume change during phase transition, leakage, and long-term cycling stability.
I observe patents that combine PCM with heat spreaders or liquid cooling plates. In one generic design, a heat-equalizing module filled with a paraffin composite is attached to battery cells. A separate heat-storage module contains PCM and heat-exchange tubes. The system can switch between cooling and heating modes. Heat-exchange circuits couple the coolant with the PCM, staggered conductive fins improve heat transfer, and an elastic partition compensates for volume changes. This is a clear example of how the electric vehicle battery pack thermal control field is moving from single-mode cooling to multifunctional thermal buffering.
In my view, PCM is not a complete replacement for active cooling in a high-power electric vehicle battery pack. It is better understood as a composite layer. It can reduce peak temperature, delay thermal runaway propagation, and smooth transient loads. Its patent future is therefore closely linked to liquid cooling and intelligent control.
Composite and intelligent thermal control
The most important future direction I identify is composite thermal management and intelligent control. The electric vehicle battery pack must operate under fast charging, high ambient temperature, low ambient temperature, high load, and long service life. No single cooling route solves all these conditions at low cost. Therefore, patents increasingly combine two or more mechanisms: liquid cooling plus PCM, refrigerant direct cooling plus heat pump, air cooling plus liquid cooling, or liquid cooling plus cabin thermal integration.
I formalize the control problem as follows. The controller seeks to keep the electric vehicle battery pack near a reference temperature while minimizing energy use:
$$T_{\text{ref}} = f(SOC, I, T_{\text{amb}}, SOH, t)$$
$$J = \sum_{k=0}^{N-1} \left[(T_k – T_{\text{ref}})^2 + \lambda u_k^2\right]$$
Here, \(u_k\) represents control inputs such as pump speed, fan speed, compressor power, or valve position. A classical proportional-integral-derivative controller can be written as:
$$u(t) = K_p e(t) + K_i \int_0^t e(\tau)d\tau + K_d \frac{de(t)}{dt}$$
I also see model predictive control concepts in recent patents. The controller predicts future heat generation from current, state of charge, and ambient conditions, then optimizes cooling power over a horizon. This is especially important for the electric vehicle battery pack during fast charging, because heat generation is highly transient.
| Future direction | Technical meaning | Patent implication for the electric vehicle battery pack |
|---|---|---|
| Integration | Combine battery, cabin, motor, and power electronics thermal loops | More system-level patents, fewer isolated component patents |
| Lightweight design | Reduce cold plate mass, coolant volume, and packaging space | Material, topology, and manufacturing patents |
| Low energy consumption | Minimize pump, fan, and compressor power | Control strategy and flow optimization patents |
| Composite thermal management | Use multiple cooling mechanisms together | Hybrid architecture patents |
| All-climate adaptation | Operate from severe cold to severe heat | Heat pump, preheating, and thermal storage patents |
| Intelligent management | Use sensing, estimation, and optimization | Algorithm, digital twin, and cloud-edge patents |
Quantitative synthesis of the field
I now synthesize the main numerical findings. The electric vehicle battery pack thermal control field is large, concentrated, and increasingly quality-oriented. China is the absolute leader by patent origin. The top applicants are highly concentrated. Liquid cooling is the current industrial mainstream. Air cooling remains mature but limited. Refrigerant direct cooling is an advanced high-performance route. PCM is a promising passive and composite route. Intelligent control is the unifying layer.
| Dimension | Key finding | My interpretation |
|---|---|---|
| Timeline | 2007-2025; four stages | From exploration to rational adjustment |
| 2015-2018 growth | 142 to 759; 434.5% total increase | Lithium-ion and policy-driven explosion |
| 2019-2024 pattern | Average about 733; 2024 peak | High-level optimization of the electric vehicle battery pack |
| 2025 adjustment | 684; about 25.3% decline | Standardization and selective filing |
| Leading origin | 96.3% share | Extreme innovation concentration |
| Top 3 applicants | 57.7% share | Oligopolistic control of core thermal patents |
| Top 5 applicants | 74.8% share | High entry barrier for latecomers |
| Enterprise share | 79.6% | Application-driven innovation |
| University share | 20.4% | Foundational support for the electric vehicle battery pack |
| Main route | Liquid cooling | Industrial mainstream |
| Future route | Composite and intelligent control | Next patent battleground |
I also quantify thermal performance objectives that appear across the electric vehicle battery pack patent set. The temperature uniformity index can be written as:
$$\sigma_T = \sqrt{\frac{1}{N}\sum_{i=1}^{N}(T_i-\bar{T})^2}$$
A normalized uniformity score is:
$$U_T = 1 – \frac{\Delta T}{\Delta T_{\max}}$$
The thermal efficiency of the cooling system can be described as:
$$\eta_{\text{th}} = \frac{Q_{\text{diss}}}{Q_{\text{gen}}}$$
The parasitic energy penalty of the electric vehicle battery pack thermal system is:
$$E_{\text{pen}} = W_{\text{pump}} + W_{\text{fan}} + W_{\text{compressor}}$$
This penalty affects range. A simple range-impact approximation is:
$$\Delta R \approx -\frac{E_{\text{pen}}}{E_{\text{pack}}} R_{\text{nom}}$$
In my view, these equations explain why patent activity is shifting toward control and integration. Improving the heat transfer coefficient is important, but reducing parasitic energy while maintaining uniformity is equally important for the electric vehicle battery pack.
Implications for design and patent strategy
I draw several implications from the patent landscape. First, the electric vehicle battery pack thermal control field is no longer a peripheral accessory market. It is a core differentiator. Second, the dominant route for current production is liquid cooling, but the strongest future patent opportunities lie in composite architectures and intelligent control. Third, applicant concentration means that new entrants must find niches such as advanced materials, low-pressure-drop channels, refrigerant distribution, thermal runaway barriers, or model-based control. Fourth, because the electric vehicle battery pack operates across climates and duty cycles, all-climate adaptation is a major source of patent value.
| Strategic area | Why it matters for the electric vehicle battery pack | Patent opportunity I see |
|---|---|---|
| Cold-climate heating | Low temperature increases resistance and reduces range | Heat pump integration, self-heating, thermal storage |
| Fast-charge cooling | High current creates rapid heat generation | Direct cooling, high-flow cold plates, predictive control |
| Temperature uniformity | Cell imbalance accelerates aging | Flow channel topology, PCM composites, adaptive valves |
| Thermal safety | Thermal runaway can propagate | Barrier materials, venting, early detection |
| Energy efficiency | Parasitic loads reduce driving range | Low-power control, waste-heat recovery |
| System integration | Battery, cabin, and powertrain share thermal needs | Multi-loop architecture and mode switching |
I also note that the electric vehicle battery pack patent field is becoming more global in value even though filings are concentrated in one origin. Safety standards, supply-chain exports, and high-value vehicle markets create incentives to file in multiple jurisdictions. Therefore, I expect future quality competition to include international family size, claim scope, and standards-essential considerations.
My outlook
My outlook for the electric vehicle battery pack thermal control field is that integration will accelerate. The electric vehicle battery pack will be managed together with the cabin, motor, inverter, and charging system. Thermal control will become a software-defined function, with sensors, state estimation, and optimization algorithms deciding how to distribute cooling and heating. Liquid cooling will remain the baseline, but refrigerant direct cooling and PCM composites will grow in specific segments. Air cooling will persist in low-cost applications but will not dominate high-performance electric vehicle battery pack designs.
I also expect patent activity to focus on four themes. The first is compact and lightweight cold plates. The second is multi-mode heat pump systems that can cool and heat the electric vehicle battery pack. The third is phase-change and high-conductivity composites. The fourth is intelligent control using digital twins, cloud-edge data, and predictive thermal models. These themes align with the physical equations I presented earlier: maximize \(Q_{\text{diss}}\), minimize \(\Delta T_{\text{cell}}\), reduce \(E_{\text{pen}}\), and maintain \(T_{\text{pack}}\) within the target window.
| Outlook theme | Expected patent focus | Effect on the electric vehicle battery pack |
|---|---|---|
| Compact cold plates | Topology optimization, additive manufacturing, low-pressure-drop channels | Higher power density and lower mass |
| Multi-mode heat pump | Valve networks, refrigerant routing, cabin-battery coupling | Better all-climate performance |
| PCM composites | High-conductivity fillers, shape-stable materials, encapsulation | Improved uniformity and thermal buffering |
| Intelligent control | State estimation, MPC, digital twin, fleet learning | Lower parasitic energy and safer operation |
| Thermal safety | Propagation barriers, venting paths, early warning | Reduced risk for the electric vehicle battery pack |
Conclusion
I conclude that the electric vehicle battery pack thermal control patent landscape has matured from a simple cooling problem into a system-level engineering and control field. The four-stage evolution from 2007 to 2025 shows a clear progression: early exploration, explosive growth, high-level optimization, and rational adjustment. China is the dominant patent origin, with a 96.3 percent share. The top applicants are highly concentrated, with the top three holding about 57.7 percent and the top five about 74.8 percent of the leading group. Enterprises dominate applications, while universities provide foundational support. Liquid cooling is the current mainstream for the electric vehicle battery pack. Air cooling remains useful in limited applications. Refrigerant direct cooling offers high-performance cooling and heating. Phase-change materials provide passive uniformity and thermal buffering. Composite thermal management and intelligent control are the most promising future directions.
For anyone designing, investing in, or protecting technology related to the electric vehicle battery pack, my patent-based view is clear: the next wave of value will not come from a single cooling component alone. It will come from the ability to integrate multiple thermal routes, sense the state of the electric vehicle battery pack in real time, predict thermal loads, and control the system with minimal energy penalty. That is the direction in which the patents, the market, and the physics all point.