Electric cars are rapidly gaining popularity, but concerns over battery costs, raw materials, weight, and charging times have fueled interest in non-battery electric vehicles. Emerging technologies like hydrogen fuel cells and in-motion charging could enable electric driving without big battery packs.
Table of Contents
- Challenges With Current EV Batteries
- Hydrogen Fuel Cells for Extended Range
- Battery-Assist Hybrid Approach
- In-Motion Wireless Charging
- Capturing Kinetic Energy Through Regeneration
- Solar Energy for Supplemental Range
- Key Considerations Going Battery-Less
- The Path Forward – Best of Both Worlds Approach
Challenges With Current EV Batteries
Today’s electric cars rely on lithium-ion batteries to store power. But they come with inherent limitations:
- High raw material costs make batteries expensive. Key materials like lithium and cobalt face potential shortages as production scales up.
- Batteries are heavy, weighing over 1000 pounds in many EVs. This impacts acceleration, handling and range. Lightweighting is crucial for performance.
- Despite range improvements, most affordable EVs still top out around 250 miles per charge. Long recharge times limit usability for long trips.
- Unknown long-term battery lifespan means replacement costs remain uncertain in the used EV market.
- Thermal runaway can lead to battery fires in severe collisions, especially if damaged.
To expand the viability of mass-market EVs, alternatives to large battery packs present promising opportunities.
Hydrogen Fuel Cells for Extended Range
Hydrogen fuel cell systems offer extended driving range without heavy batteries. A fuel cell combines stored hydrogen and atmospheric oxygen to generate electricity continuously when underway.
Advantages of hydrogen fuel cell EVs:
- Fuel tanks weigh far less than equivalent energy storage in batteries.
- Quick refueling with pressurized hydrogen vs. hours of recharging. 300+ mile range is readily achievable.
- Only byproduct from the reaction is water, so zero-emissions operation.
- Proven durability with fuel cells already used extensively in transit applications.
But infrastructure challenges remain before fuel cell cars gain mainstream popularity:
- Hydrogen production and distribution networks require massive expansion and cost reductions to be viable at scale.
- Fuel cell stacks remain extremely expensive compared to internal combustion engines.
- Efficiency limitations cause fuel cell EVs to consume more total energy than battery EVs per mile.
With improved economies of scale, fuel cell systems show promise for long-range electric driving without heavy battery packs.
Battery-Assist Hybrid Approach
Smaller batteries can be right-sized when partnered with another onboard power source in hybrid EVs. The assist battery handles burst power demands:
- Acceleration – the battery provides full torque from a stop and at lower speeds.
- Regenerative braking – the battery captures braking energy, reducing wear on friction brakes.
- Supplementary power – the battery helps meet peak loads to prevent engine/generator strain.
With sustained high-power needs met by an engine-driven generator, the battery only needs capacity for bursts. Range exceeds pure battery EVs while minimizing battery size and cost. However, hybrids still require fossil fuels.
In-Motion Wireless Charging
Inductive charging while driving could continuously replenish a small onboard battery through electromagnetic fields:
- Charging plates embedded in the roadway transfer energy wirelessly to coils on the EV chassis.
- This allows a relatively small battery just large enough to cover the gap between charging zones.
- Fast charging while in motion eliminates range anxiety and long charging stops.
But major infrastructure investment is needed for widespread adoption:
- Costly changes to install charging plates on highways and heavily transited routes.
- Upfront vehicle costs higher due to onboard receivers and safety isolation equipment.
- Charging zones must be close enough together to prevent interruptions in power.
In-motion charging remains years from mass deployment but offers potential for minimal battery EVs.
Capturing Kinetic Energy Through Regeneration
Innovative regenerative systems could harvest energy from the vehicle’s momentum and movement:
- Flywheel systems convert kinetic energy to stored electricity when slowing down. This charges an onboard battery.
- Suspension travel pumps captured by hydraulic actuators can also generate electricity from up-down motion.
- Piezo generators produce power by compressing specialized crystals as the vehicle weight shifts.
- Small wind turbines activated by forward movement also present possibilities.
Such technologies could passively charge an EV battery without external electricity. But practical applications require major breakthroughs in efficiency and energy density. They are still conceptual.
Solar Energy for Supplemental Range
Solar panels on electric car roofs can add a few miles of driving range per day by capturing sunlight. While not enough for full battery-less operation, benefits include:
- Slowly recharging the battery through passive solar energy during daytime driving.
- Reducing drain on the grid when parked in sunny areas.
- Powering accessories like interior climate control without tapping the battery.
However, limited roof space sharply restricts solar harvesting capabilities. Panels may provide only 10-25 miles of range over 8 hours of sun.
Key Considerations Going Battery-Less
Pursuing non-battery electric mobility requires evaluating:
- Maturity level – battery EVs are proven and expanding, while alternatives remain largely conceptual.
- Infrastructure needs – hydrogen and in-motion charging require major networks.
- Cost analysis – fuel cells and added complexity affect affordability.
- Efficiency impacts – some technologies waste more total energy than batteries.
- Convenience factors – refueling times, charging intervals, range limits.
- Sustainability – must move transport away from fossil fuel dependence.
For now, incrementally improved batteries appear most viable. But exploring alternatives nudges innovation forward to expand EV adoption in the mainstream.
The Path Forward – Best of Both Worlds Approach
Exciting possibilities exist to minimize or eliminate bulky battery packs in future EVs. But a multipronged strategy using the strengths of different technologies likely offers the fastest path to mass EV adoption:
- Right-sized batteries to handle base loads, daily commuting, and efficiency.
- Supplementary technologies like solar panels and regeneration to extend range.
- Fuel cells and in-motion charging for long trips and flexible refueling.
Engineers must optimize these technologies in parallel to capitalize on their combined potential. Affordability at scale remains the overarching challenge. But the most effective solution may be an intricately orchestrated vehicle energy ecosystem, not a single silver bullet.
While lithium-ion batteries currently dominate electric cars, alternatives like hydrogen fuel cells, in-motion charging, and energy harvesting systems present opportunities to slash battery size or go battery-less. These innovations address issues like cost, charging times, and range anxiety. However, major technology leaps and infrastructure investment are still required for mass viability. Nearer-term advances will likely combine right-sized batteries with supplementary systems for an optimized balance of efficiency, convenience and affordability. This underscores that electric transportation remains a work in progress with the most compelling possibilities still on the horizon.