Evolution of Power Supply for Portable Medical Devices: Will Nickel-metal Hydride Batteries Be Replaced by Lithium Batteries?

Evolution of power supply for portable medical devices: Will nickel-metal hydride batteries be replaced by lithium batteries?

Introduction: Technological evolution of power supply for medical devices

With the intelligent and lightweight development of portable medical devices (such as blood glucose meters, ultrasound machines, defibrillators, etc.), their power supply technology is also constantly innovating. For a long time, nickel-metal hydride (Ni-MH) batteries have occupied an important position in the medical field due to their stability and safety. However, in recent years, lithium-ion (Li-ion) batteries have rapidly emerged with advantages such as higher energy density and longer life. So, will nickel-metal hydride batteries be completely replaced by lithium batteries? This article will conduct an in-depth analysis from the dimensions of technical performance, safety, cost, application scenarios, etc., to explore the future trend of power supply for portable medical devices.

1. Technical performance comparison: lithium batteries are leading in all aspects?

(1) Energy density: lithium battery has overwhelming advantages

Nickel-metal hydride battery: 60-120Wh/kg

Lithium battery: 150-250Wh/kg (some high-end lithium batteries can reach more than 300Wh/kg)

Conclusion: lithium batteries can provide more than twice the battery life at the same volume, and are more suitable for equipment that needs to work for a long time (such as dynamic electrocardiogram monitors).

(2) Cycle life: lithium batteries are more economical

Nickel-metal hydride battery: 500-1000 cycles (there is memory effect)

Lithium battery: 1000-2000 cycles (no memory effect)

Conclusion: It is more cost-effective to use lithium batteries for high-frequency medical equipment (such as portable ultrasound in hospitals).

(3) Charging speed: lithium battery fast charging has obvious advantages

Nickel-metal hydride battery: usually takes 4-6 hours to fully charge

Lithium battery: can be charged to 80% in 1-2 hours (supports fast charging technology)

Conclusion: In emergency and rescue scenarios, lithium batteries can better meet the needs of rapid replenishment.

2. Safety: Are nickel-hydrogen batteries still the "safety trump card"?

Despite the continuous advancement of lithium battery technology, the risk of thermal runaway is still its biggest shortcoming:

Nickel-hydrogen batteries: use aqueous electrolytes, are not easy to ignite and explode, and are suitable for high-risk environments such as operating rooms and ICUs.

Lithium batteries: need to rely on BMS (battery management system) to prevent overcharging/overdischarging, and may still fail under extreme conditions.

Case: FDA once recalled some portable defibrillators using inferior lithium batteries due to the risk of failure under high temperatures.

Conclusion: In life support equipment, nickel-hydrogen batteries are still a safer choice.

3. Cost factors: Is the low-end market still dominated by nickel-hydrogen?

Initial cost: The price of nickel-hydrogen batteries is about 1/2 to 1/3 of that of lithium batteries, which is suitable for primary medical equipment with limited budgets.

Long-term cost: Lithium batteries have a longer lifespan and the comprehensive use cost may be lower.

Market status:

High-end equipment (such as wireless ultrasonic scalpels and smart insulin pumps) has generally turned to lithium batteries.

The low-end market (such as basic blood glucose meters) still widely uses nickel-metal hydride solutions.

4. Future trends: coexistence or substitution?

(1) Evolution of lithium batteries

Solid-state lithium batteries: completely solve the flammability problem and increase energy density by more than 50%.

Flexible batteries: adapt to wearable medical devices (such as patch-type electrocardiographs).

(2) NiMH battery’s stronghold

Regulatory requirements: some medical safety standards still limit the use of NiMH systems.

Special electrochemical requirements: such as defibrillator devices that require instantaneous high current output.

Experts predict:

From 2025 to 2030, the market share of lithium batteries in portable medical devices will increase to more than 70%.

However, NiMH batteries will exist in specific fields for a long time, and complete replacement will take at least 10-15 years.

Conclusion: Rationally view technology iteration

Mainstream replacement is a foregone conclusion: In most portable medical devices, lithium batteries are gradually replacing NiMH batteries.

Irreplaceable niche market: NiMH solutions are still needed for high safety and high instantaneous power demand scenarios.

The future belongs to new technologies: solid-state lithium batteries may end this competition, but at this stage, the two still need to coexist.

Medical device manufacturers should choose power solutions based on specific needs rather than blindly follow technological trends. For end users, it is far more important to pay attention to the actual battery life and safety certification of the device than to worry about the battery type.