October 12, 2022

Atotech explores challenges and opportunities for the finishing industry as it navigates the transition into the electric vehicle market

By Darrick Gula

What once was a niche market dominated by one OEM is now gaining full steam as new startups to legacy OEMs have all announced dates to have full electric vehicle (EV) fleets hitting the market. EVs are clearly no longer a fad.  With the tremendous upcoming growth in the EV market, and less internal combustion engine (ICE) vehicles being produced, what does this mean to the finishing industry? 

It can be scary times if you are highly involved with the current automotive market.  There are many questions from those who supply parts for the automotive industry.  What does this mean for current processes and part components?  What will be eliminated and what will be added?  Which parts will remain unchanged and what parts will be revised?   All these questions can’t be answered in just one article, but we can give an overview of some of the challenges. 

Regardless of the unknown variables that will affect the speed of adoption of EVs, one thing is certain, there will be a shift in production from current ICE production to more new EV models.   This will create lower volumes of production for standard ICE components and add new opportunities requiring different finishes and technology. 

It is obvious that current drive train (engine/transmissions/differentials/drive shafts) along with current cooling, fueling and exhaust systems will all be lost in the transition.  But what are some new areas that will require surface finishing? 

Quite a bit of the new components will be non-moving and electrical in nature.  These will include the battery pack, e-motors, inverter and power control units, and high voltage electrical distribution, along with new thermal management systems.  The lack of drive belts on engines will require a new approach for other systems including HVAC, power steering, and braking systems. 

Battery packs are at the heart of an EV.  A typical breakdown of the battery packs can be found in Fig. 1.A, and an example of applicable surface finishing in Fig 1.B.  There will be many systems within this module, from the battery cell to the housing and all the components inside.  What will complicate the solutions in the short term is that every manufacturer is taking different approaches.  This includes the materials uses as well as how they will be assembled.  Will they be constructed with plated fasteners or use more adhesives and other joining approaches?  Will they be made of aluminum, steel, or composites? In some cases, they use a combination of materials.

The materials used will drive the necessary surface finishing involved with the product.  In the case of aluminum, pretreatment, conversion coatings and topcoats are very important.  This coating often requires specific dielectric strength or thermal properties along with superior adhesion.  With steel, pretreatment and corrosion control (Zn, ZnNi, Electroless Ni) also become important.  Assembly components inside the module often need high dielectric strength coating to avoid shorting or stray current.

The battery cells often bring different surface finishing needs depending on the style of battery.  From corrosion inhibitors, adhesion promotors and copper and nickel plating.  These components will have very high surface areas in these large arrays of batteries and the millions of batteries that will need to be produced. 

Moving all this current from battery cells to the motors requires a lot of effort and requires components to be connected in construction and to minimize resistance along with the proper corrosion control.  Components would include busbars, connectors, and lead tabs.  Depending on the style of connection or serviceability there will be different coatings required.  These would include silver, tin and gold with nickel sulfamate, often with an anti-tarnish for corrosion control.  Silver is always a great conductor, but high costs will limit usage.  Where there is sufficient clamping force and limited removal of the joint, nickel and tin offer very attractive performance.  Coatings such as hard silver will be important for high usage connectors such as the charge port, which will see thousands of mating cycles. 

Fasteners will be another interesting topic in the move to EVs.  Many fasteners will be necessary for current EVs, although the total number of threaded fasteners will vary according to design of the battery modules and how components will be fastened. 

New challenges lie ahead for threaded fastener usage in EVs.  Some connections require conductivity, while others will require insulation.  Also, bimetal corrosion becomes a consideration due to the increase in lightweight materials used, which will challenge the current fastener materials and coatings utilized.  Light weighting will be important in future designs. Electroless nickel could see many opportunities within EVs, including auxiliary systems such as air conditioning compressors, thermal heat exchangers and various other components. 

Another growing opportunity is EMI shielding of components used in various applications such as inverters.  There will be opportunities to electroplate composite materials with copper/nickel iron rather than a metallic base material to save weight and give the required EMI shielding properties. 

It’s doubtful that most people were expecting to see such a fast-paced change to get this many EV models to market in such a short time.  Many OEMs are racing to get new models on the market and fill the initial demand cycle.  This is driving shorter and more challenging product development cycles for an industry that has limited maturity.  Many of the challenges and products are new and existing specifications or standards are not currently in place.  This is a time where new technology can quickly grow, which is difficult in an industry that typically takes longer than average to accept change.  It is important to work together to ensure that our industry has the right processes and products to meet the demands of components of these new vehicles.

Many headwinds still exist for a full conversion away from ICE cars, and some feel hybrid technology may be a good bridge for some time. With that said, it’s safe to say ICE will have a place in the near future, and this transition will not happen overnight as it still requires quite a bit of investment from the OEMs along with our infrastructure.  One thing that is certain is that we are currently seeing strong trends towards EVs and they currently remain the focus of the future of the automotive industry.  As an automotive supplier, is your company working on a plan to prepare your path to future success in the EV revolution?

Darrick Gula is the North American Regional OEM Manager for Atotech and MKS Instruments Inc. Atotech is a specialty chemicals technology company, that specializes in advanced electroplating solutions. Atotech delivers chemistry, equipment, software, and services for innovative technology applications through an integrated systems-and-solutions approach