The energy density of lithium-ion batteries—measured in watt-hours per kilogram (Wh/kg) or per liter (Wh/L)—significantly influences both their cost and durability.
Impact on Cost
- Higher energy density generally means more energy storage per unit weight or volume, enabling lighter and smaller batteries for the same capacity. Achieving higher energy density often requires advanced materials and design optimizations, such as ultrathin current collectors to minimize auxiliary materials, which can increase manufacturing complexity initially.
- Over the past decades, lithium-ion battery energy density has increased substantially (e.g., volumetric energy density rising from about 55 Wh/L in 2008 to around 450 Wh/L by 2020), while their cost per energy unit has dropped roughly tenfold since their introduction in the early 1990s.
- Current lithium-ion batteries typically have energy densities in the range of 200–330 Wh/kg, with cutting-edge designs reaching even higher levels (e.g., 711 Wh/kg in recent experimental batteries).
- The cost of lithium-ion batteries is often expressed as US$ per kWh; higher energy density can reduce cost indirectly by lowering the amount of raw materials and weight required for a given energy capacity, although achieving very high energy density may involve costlier materials or manufacturing techniques initially.
Impact on Durability
- Increasing energy density often involves pushing cell voltages higher or using electrode materials that store more lithium, which can stress the battery chemistry and reduce cycle life if not managed carefully.
- Typical lithium-ion batteries have cycle lives ranging from 400 to 1,200 full charge-discharge cycles.
- There is a tradeoff between energy density and durability: maximizing energy density can sometimes compromise battery lifespan due to faster degradation mechanisms, such as electrode material breakdown or electrolyte decomposition.
- Battery designs that optimize the proportion of active materials while minimizing inactive components can help maintain durability even at high energy densities.
Summary
| Aspect | Effect of Higher Energy Density |
|---|---|
| Cost | Can reduce cost per kWh by requiring less material per energy unit, but may increase complexity and initial manufacturing costs; overall historical trend shows energy density improvements driving cost reductions. |
| Durability | Potentially reduces cycle life due to increased chemical and mechanical stresses; needs careful design to balance longevity and capacity. |
In conclusion, higher energy density in lithium-ion batteries tends to lower the effective cost of energy storage by increasing capacity for a given size and weight, but may challenge durability if battery chemistry and design are not optimized to handle these stresses. Advances in battery technology continue to push energy densities higher while seeking to maintain or improve cycle life and reduce costs.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-energy-density-of-lithium-ion-batteries-affect-their-cost-and-durability/
