how-far-exactly-can-an-ev-travel

Display portlet menu

how-far-exactly-can-an-ev-travel

Display portlet menu

How far exactly can an Electric Vehicle (EV) travel?

smart car driving towards a sunset

Since 2017, many countries have announced or begun setting timelines for banning sales of conventional vehicles. This is exciting yet unsettling news for automobile makers.  On one hand the direction has been set, removing any lingering hesitation but on the other hand, purely from the perspective of recharge mileage, few commercially available EVs fulfill consumer expectations at this moment. To date, the 500km range achieved by Tesla’s Model S still holds the record in terms of EV development.

Electric Vehicle

Diagram 1: Highest mileage range of various Tesla S models (Source: Tesla)

 

Moreover, market incentives have already declined before technical barriers can be overcome. This June, China's Ministry of Finance adjusted its EV subsidy policy by removing subsidies for new energy vehicles with ranges of less than 150 km. Only vehicles with mileage above 300 km are eligible for subsidies comparable to those offered in 2017. The mindset behind this change is clear: funding is targeted to support EV makers that possess more advanced technologies. The crowding out effect has already manifested, with data showing that sales in June are 22% lower than May.

Therefore, "how far can an EV travel" is no longer just a question of mileage range technology but also one of great concern to businesses within the field, or rather how much more the industry can achieve. Quite understandably, this has become a major issue of concern.

From the technical perspective, two problems must be resolved so EVs can "travel further": increasing energy density and conserving energy. "Increasing energy density" pertains to improvements in power battery technology so that vehicles are equipped with higher energy capacity while "conserving energy" refers to better battery control and management so as to improve operational safety efficiency and optimize potential. This is where BMS comes into play.

Let us temporarily put aside unrealized technologies not yet commercially viable and focus on lithium ion battery technologies that are already in use commercially or nearing market launch. Lithium ion batteries are typically categorized according to the electrode material used. Types that can be categorized by their use of cathode materials include the lithium manganese battery, lithium manganese iron phosphate battery, lithium iron phosphate battery, and ternary battery. Categorized by the use of anode materials, they can be differentiated into graphite and lithium titanate batteries. See Table 1 for the performance and properties of these batteries.


Performance comparison of lithium primary batteries

Among them, lithium manganese batteries melt easily under high temperatures and perform poorly in terms of stability and safety. Lithium manganese iron phosphate batteries are not yet technologically mature and have a short lifespan. Neither of the above are therefore suitable for powering EVs. Lithium iron phosphate batteries exhibit stable voltage and are economical, able to withstand temperatures up to 800℃, and highly safe. For these reasons, they are widely applied in electric passenger cars that require high battery energy levels, long run time, extended lifespan, and high safety performance. Meanwhile, ternary batteries have high energy density, long lifespans, and are able to withstand temperatures of up to 200℃, but cannot be manufactured into high capacity single cells due to safety constraints. They are however becoming increasingly prevalent in the passenger car market where demands on spatial constraints, mileage range and energy density are high. For example, Tesla uses ternary batteries supplied by Panasonic.

Innovation in anode materials is another key to improving battery performance. Lithium-metal dendrite precipitates on the surface of the carbon electrode during overcharge that can pierce the membrane separator in the middle of the battery, causing internal short-circuit and thermal runaway. This has always been one of the safety concerns of lithium ion batteries. If lithium titanate is utilized as the anode material, however, lithium-metal dendrite will not precipitate, thereby eliminating the risk of thermal runaway. Such batteries perform well in low temperatures, exhibit high power efficiency, and can be charged up to 10,000 cycles. Lithium titanate batteries nevertheless have several disadvantages such as high temperature flatulence, lower inherent voltage, and high cost. Therefore, they are currently used mainly in low range scenarios or hybrid vehicles, and do not contribute much to a longer traveling distance. It is worth noting, however, that lithium titanate batteries have the advantage of fast recharging, a feature that may change user conceptions of battery charging from " charge once for a longer distance" to "recharge along the way".

Developing new battery technologies and enhancing battery mileage range are now no longer the objectives of individual enterprises, but have escalated into national strategies. Countries all around the world are now formulating plans to develop power battery technologies. For example, the US Department of Energy has proposed a series of technological improvements to increase battery energy density from 100W.h/kg in 2012 to 250W.h/kg in 2017, while China plans, in its "13th Five-Year Plan", to phase in batteries with 300W.h/kh energy density for commercial use and begin development of batteries with 400-500W.h/kg energy density.

Even though we have yet to identify a clear winner from existing power battery technologies, and a perfect solution for EV application has yet to emerge, the sheer amount of resources that have been poured into relevant developments can perhaps serve as assurance that future prospects remain bright.

 

 

 

 

how-far-exactly-can-an-ev-travel

Display portlet menu

how-far-exactly-can-an-ev-travel

Display portlet menu
Related Articles
2D image of smart phone charging on mobile battery
Why does Iq matter for USB Type-C?
November 11, 2019
This change is driving an increase in demand for Type-C AC/DC chargers and power banks because the Type-C connector has flip capability which gives convenience to users.
avnet branded USB type C connector
It is time to say goodbye to Micro USB!
November 11, 2019
Type-C’s greatest advantage is its integration capability. In addition to not having a right or wrong side (a perennial problem for Micro USB users), Type-C is able to offer integrated power delivery (PD) during charging.
Using Programmable Logic to Build Power-Efficient Systems
October 29, 2019
The successful implementation of the Internet of Things (IoT) requires new thinking about how to power connected devices.
Woman jogger wearing a bluetooth running tracker
6 reasons why startups choose Bluetooth for their projects
July 26, 2018
Bluetooth technology originated in the 1990s, but its primary function was device-to-device (or point-to-point) protocol for securely sharing data between devices in close proximity. Think less music streaming, more wireless printers.
Battery powering
Batteries are key to charging options
July 6, 2018
Wired power is a strong option for developers that need to get to market fast and require an inexpensive, proven solution. For products where convenience and future compatibility are paramount, you can move forward confidently with standards-based wi
smart devices on charge pad: phone, watch and tablet
With the rising popularity of 7.5W wireless charging, Avnet helps companies obtain rapid product certification
February 25, 2018
The current wave of wireless charging technology, fueled by the new iPhone from Apple, is showing strong momentum growth. Semiconductor suppliers around the world have started making substantial investments in new IC solutions while a low barrier to
Person checking battery charge level on their cell phone
3 levels of Qi testing
November 24, 2017
You’ve designed, prototyped and built a revolutionary product with cutting edge Qi technology – congrats! Before you get to officially certifying your Qi product, you’ll need to do some testing to ensure its veracity.
man pulling smartphone from pocket
Watch for these two problems in your Qi wireless charging project
November 14, 2017
Here are two of the most common problems engineers face in integrating Qi wireless charging in their projects.
charging cell phone in automobile
How to get your Qi project certified by the Wireless Power Consortium
November 14, 2017
By aligning with the Wireless Power Consortium and Qi standard—the way big name brands like Apple, Samsung and Avnet have—you can help verify the quality of your product to new customers.
Bill Amelio, Avnet CEO
Qi standard is for more than just smartphones
By Bill Amelio   -   November 14, 2017
I’m not alone in my suspicion that the engineering world will soon follow a singular standard for wireless charging: the Qi standard. I think it would be the right move—and its impact would extend far beyond the charging of mobile phones.
side view of a sports car from the ground up
Understanding the Power of Battery Management Systems
August 28, 2017
According to estimates, China's EV battery market will reach RMB 120 billion by 2010, at which time the EV BMS market is expected to be valued at RMB 17 billion. Although the cost of BMS relative to the entire EV is relatively low, developers should
man drawing schetch of an electric car attached to a battery
Technologies and Components for Designing Electric Vehicles
April 29, 2017
Hybrid electric vehicles (HEVs) such as the Toyota Prius and the Chevy Volt and electric vehicles (EVs) such as the Nissan Leaf, BMW i3 and Tesla Model S are growing in popularity amid concern for global warming.
energy harvesting concept with green batteries sprouting from the ground
Powering the Internet of Things via Energy Harvesting
April 25, 2017
The push is on to add Internet capability to everything—often called the Internet of Things (IoT)—and the challenge for design engineers is to figure out how to power each of these IoT nodes.
chart depicting device power states
Power Management Techniques for Low-Energy IoT Devices
March 24, 2017
With the rise of the Internet of Things (IoT), embedded designers are, more than ever, focusing their attention and efforts on system energy usage.
nurse checking person wearing health monitoring system on wrist
Internet of Things: Designing Sensor-Based Devices with Coin Cell Batteries
March 13, 2017
A popular vision of the Internet of Things (IoT) is that it will comprise billions of sensors gathering information about their local environment and transmitting that data back to servers in the cloud. Such data will be compiled, analyzed and shared

how-far-exactly-can-an-ev-travel

Display portlet menu
Related Events

No related Events found